Devices and methods for body fluid sampling and analysis

ABSTRACT

Described here are meters and methods for sampling, transporting, and/or analyzing a fluid sample. The meters may include a meter housing and a cartridge. In some instances, the meter may include a tower which may engage one or more portions of a cartridge. The meter housing may include an imaging system, which may or may not be included in the tower. The cartridge may include one or more sampling arrangements, which may be configured to collect a fluid sample from a sampling site. A sampling arrangement may include a skin-penetration member, a hub, and a quantification member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/215,468, filed Dec. 10, 2018, which is a continuation of U.S.application Ser. No. 15/697,311, filed Sep. 6, 2017, which issued asU.S. Pat. No. 11,051,734 on Jul. 6, 2021, which is a continuation ofU.S. application Ser. No. 13/566,886, filed Aug. 3, 2012, which issuedas U.S. Pat. No. 9,782,114 on Oct. 10, 2017, which claims priority toU.S. Provisional Application No. 61/514,872, filed on Aug. 3, 2011, eachof which is hereby incorporated by reference in its entirety.

FIELD

The present invention relates to devices and methods for sampling,collecting, and analyzing a fluid sample (e.g., one or more body fluids)

BACKGROUND

Diabetes is a widespread condition, affecting millions worldwide. In theUnited States alone, an estimated 23.6 million people, or 7.8% of thepopulation, have the condition. Diabetes accounts for an estimated $174billion annually in direct and indirect medical costs. Depending on thetype (Type 1, Type 2, and the like), diabetes may be associated with oneor more symptoms such as fatigue, blurred vision, and unexplained weightloss, and may further be associated with one more complications such ashypoglycemia, hyperglycemia, ketoacidosis, neuropathy, and nephropathy.

To help prevent these undesirable complications, it may be necessary forpeople with diabetes to monitor one or more blood analyte levels, suchas blood glucose. Glucose testing allows a patient to ensure that his orher blood glucose is at a safe level, which in turn may help monitor theeffectiveness of diet, medication, and exercise in controlling thepatient's diabetes, and may also help reduce the risk of developing oneor more diabetes-related conditions (e.g., blindness, kidney damage andnerve damage). Many of the currently available glucose meters, however,require numerous components and complicated steps to complete a test,and often do not allow for discreet testing. This may reduce thelikelihood of user compliance. As such, it may be desirable to producesafe and effective analyte concentration meters that may make samplingdiscrete and easier for the user and reduces the number of separatecomponents a patient must carry.

BRIEF SUMMARY

Described here are meters and methods for sampling, transporting and/oranalyzing a fluid sample. In some variations, a meter as described heremay comprise a meter housing and a cartridge. In some of thesevariations, the cartridge and/or the meter housing may be reusable. Inother variations, the cartridge and/or the meter housing may bedisposable.

The cartridges described here may comprise at least one cell. In somevariations, a cartridge may comprise a single cell. In other variations,a cartridge may comprise a plurality of cells. One or more portions ofthe cartridge may be covered by one or more covering materials. In somevariations, the covering material may be opaque or otherwiselight-blocking. One or more walls of the cartridge may comprise one ormore transparent viewing windows, which may allow light to enter and/orexit one or more cells. The cartridge may comprise one or more recessesor other structures for receiving a portion of the meter housing.

The cartridges may comprise at least one sampling arrangements. In somevariations, a cartridge may comprise a single sampling arrangement. Inother variations, the cartridge may comprise a plurality of samplingarrangements. When a cartridge includes a plurality of samplingarrangements, the sampling arrangements may be positioned in one or morecells. In some variations, each of the plurality of samplingarrangements is located in a different cell. In some variations, acartridge comprises one or more cell housing two or more samplingarrangements. In some variations, the sampling arrangements may comprisea member for collecting a fluid sample. In some of these variations, themember may comprise a penetration member (e.g., a needle, a solidlancet, or the like). The sampling arrangements may comprise a hub. Thehub may be configured to connect the sampling arrangement to thecartridge. In some variations, the hub may comprise one or more pinsrotatably connecting the sampling arrangement to the cartridge. In somevariations, the sampling arrangement comprises a spring (e.g., atorsional spring, a linear spring, leaf spring) or another actuator thatmay move the sampling arrangement relative to the cartridge. In somevariations, the sampling arrangement may comprise a quantificationmember. In some variations, the quantification member may comprise areagent pad.

In some variations, the hub may comprise a patterned surface. In somevariations, the patterned surface may comprise a fluid inlet. The fluidinlet may be fluidly connected to a penetration member or other fluidsource. In some variations, the patterned surface may comprise aplurality of posts configured to spread fluid received from the fluidinlet. In some variations, the patterned surface comprises a pluralityof channels and a plurality of flow diverters, wherein each channel ispositioned between two of the plurality of flow diverters.

The meter housings described here may be configured to engage withand/or hold a cartridge. In some variations, a cartridge may be insertedinto a cartridge-receiving chamber of the meter housing. In someinstances, insertion of a cartridge into a meter housing may cause thecartridge to engage a tower within the meter housing. In somevariations, the tower may be fixed relative to the rest of the meterhousing. In other variations, the tower may be movable relative to therest of the meter housing. For example, in some of these variations, thetower may be rotatably coupled to a pin, which is slidably coupled to aportion of the meter housing. In some of these variations, a spring maybias the moveable tower toward one end of the meter housing.

In some instances, insertion of a cartridge into a meter housing mayplace a cartridge cell between a light source and a light detector. Inthese variations, the light source may direct light through a viewingwindow of the cartridge and into the cartridge cell, and the lightdetector may be configured to detect any light passing through thecartridge cell (e.g., by one or more breaks or imperfections in acovering material).

The meters described here may be used to sample and analyze one or morefluid samples (e.g., blood) to determine the concentration of one ormore analytes (e.g., glucose) contained therein. In some variations, auser may initiate a testing procedure by placing pressure against aport. In some of these variations, application of pressure to the port(e.g. via a contact pad) causes a cartridge and tower to move relativeto the meter housing. In some instances, this movement may cause thecartridge and/or tower to engage an activation element, which may theninitiate a testing procedure. During a testing procedure, a samplingarrangement may be activated to collect, transport and/or react with afluid sample, as will be described in more detail below.

In some variations, a meter may comprise a meter housing comprising atower and an imaging system; and a cartridge insertable into the meterhousing and comprising a plurality sampling arrangements. In somevariations, the tower may be held inside the meter housing, and thetower may be configured to engage the cartridge. In some of thesevariations, at least a portion of the tower may fits within a recess inthe cartridge when the tower engages the cartridge. The imaging systemmay be housed at least partially within the tower. The imaging systemmay comprise a light-generating assembly and a light-receiving assembly.In some variations, the meter may be configured to position thecartridge to align a first sampling arrangement of the plurality ofsampling arrangements with the imaging system. The first samplingarrangement may be moveable between a pre-fired position and a restposition. In some variations, a torsional spring may be configured tomove the first sampling arrangement between the pre-fired position and arest position. In some variations the first sampling arrangement maycomprise a latch configured to hold the first sampling arrangement inthe pre-fired position. In some variations the meter may furthercomprising a triggering mechanism to release the first samplingarrangement from the pre-fired position. In some of these variations thetriggering mechanism comprises a vacuum pin.

In some variations, the light-receiving assembly may be configured toimage a portion of the first sampling arrangement when the firstsampling arrangement is in the rest position. In some variations, thefirst sampling arrangement may comprise a reagent pad having a midline,and the light-receiving assembly may be configured to image a portion ofthe reagent pad when the first sampling arrangement is in the restposition. In some variations the light-receiving assembly comprises alinear detector array, and the light-receiving assembly may beconfigured to image a linear viewing area of the reagent pad when thefirst sampling arrangement is in the rest position. In some of thesevariations, the linear viewing area may be positioned on a first side ofthe midline when the first sampling arrangement is in the rest position.In some variations, rotation of the first sampling arrangement from theresting position toward the pre-fired position moves the viewing area ina direction toward the midline. The first sampling arrangement mayfurther comprise a cap positioned over at least a portion of the reagentpad, wherein the light-receiving assembly is configured to image aportion of the reagent pad and a portion of the cap. In some of thesevariations, the light-receiving assembly is further configured to imagea portion of an open space on at least one side of the cap. In some ofthese variations, the meter may be configured to cancel more one or morereadings from the light-receiving assembly when light received by theportion of the light-receiving assembly imaging the portion of the openspace reaches a predetermined threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D depict an illustrative variation of the meters describedhere.

FIGS. 1A and 1B depict front and perspective views, respectively, of anillustrative variation of a meter housing. FIG. 1C depicts a perspectiveview of a variation of a cartridge suitable for use with the metersdescribed here. FIG. 1D depicts a cross-sectional side view of the meterhousing of FIGS. 1A and 1B with the cartridge of FIG. 1C insertedtherein.

FIGS. 2A-2D illustrate a variation of a cartridge suitable for use withthe meters described herein. FIG. 2A depicts a bottom perspective viewof the cartridge. FIG. 2B shows a cross-sectional side view. FIGS. 2Cand 2D depict a top perspective view and a partial-top perspective view,respectively.

FIGS. 3A-3E illustrate a variation of a sampling arrangement suitablefor use with the meters described here. FIGS. 3A and 3B show a side viewand an exploded perspective view, respectively, of the samplingarrangement. FIGS. 3C-3E illustrate a method by which a samplingarrangement may move relative to a cartridge.

FIG. 4 illustrates one variation of a hub comprising a patterned surfacesuitable for use with the sampling arrangements described here.

FIGS. 5A-5C illustrate different variations of caps suitable for usewith the sampling arrangements described here.

FIGS. 6A-6D illustrate one variation of a meter housing suitable for usewith the meters described here. Specifically, FIGS. 6A-6C show a frontview, a partial cross-sectional front view, and a cross-sectional sideview, respectively, of meter housing. FIG. 6D shows a cross-sectionalside view of the meter housing with a cartridge inserted therein.

FIG. 7A shows a front view of one variation of a tower suitable for usewith the meters described here. FIG. 7B shows a partial cross-sectionalside view of the tower of FIG. 7A engaging with a variation of acartridge suitable for use with the meters described here.

FIGS. 8A-8C illustrate one variation of a trigger mechanism suitable foruse with the meters described here.

FIGS. 9A and 9B depict an illustrative variation of an imaging systemsuitable for use with the meters described here.

FIGS. 10A and 10B illustrate another variation of a tower suitable foruse with the meters described here.

FIGS. 11, 12A and 12B illustrate variations of meter housings comprisingcartridge ejection mechanisms.

FIGS. 13A-13C depict an illustrative variation of a cartridge comprisinga single sampling arrangement.

FIG. 14 depicts a variation of a sampling arrangement depicting aviewing area that may be imaged by the imaging systems described here.

FIG. 15A depicts a variation of a sampling arrangement depicting aviewing area that may be imaged by the imaging systems described here.FIG. 15B depicts a trace that may be collected by visualization of theviewing area of FIG. 15B.

FIGS. 16A-16C illustrate a variation of meter comprising a cartridge andan imaging system.

FIGS. 17A and 17B depict a perspective view and a top view,respectively, of one variation of a hub comprising a patterned surfacesuitable for use with the sampling arrangements described here.

FIGS. 18A and 18B depict a variation of a sampling arrangement depictinga viewing area that may be imaged by the imaging systems described here.

FIG. 19 depicts a variation of a sampling arrangement depicting aviewing area that may be imaged by the imaging systems described here.

FIGS. 20A-20C depict variations of sampling arrangements suitable foruse with the meters described here.

FIGS. 21A and 21B illustrate a perspective view and a side view,respectively, of one variation of a tower suitable for use with themeters described here.

FIGS. 22A and 22B depict a perspective view and a top view,respectively, of one variation of a hub comprising a patterned surfacesuitable for use with the sampling arrangements described here.

DETAILED DESCRIPTION

Described here are meters and methods for sampling, transporting and/oranalyzing a fluid sample. The fluid sample may comprise any suitablefluid, such as, for example, one or more solutions (e.g., a controlsolution), mixtures, body fluids (e.g., blood, saliva, or the like),combinations thereof and the like. These fluid samples may be drawn fromany suitable sampling site, for example, one or more body sites (e.g.,fingers, toes, other skin surfaces, or the like) or one or moreartificial containers (e.g., a vial holding a control solution or a bodyfluid sample). Once a fluid sample is collected, it may be analyzed tomeasure one or more parameters of the fluid sample. For example,analysis of the sample may include determining the concentration of oneor more analytes in the sample. The meters may be configured to measurethe concentration of any suitable analyte (e.g., hormones, proteins,enzymes, toxins, drugs, other molecules, or the like). In somevariations, the meters described here may be configured to measure theglucose concentration of one or more blood samples or otherglucose-containing solutions.

In some variations of the meters described here, the meter may comprisea meter housing and one or more cartridges, each of which will bedescribed in more detail below. The meters may be fully integrated, inthat the meter housing and the cartridge (or cartridges) may contain allof the components necessary for collecting, transporting, and/oranalyzing a fluid sample. In some variations, the meter may beconfigured to collect and analyze a plurality of fluid samples. Forexample, in some variations, a cartridge may comprise one or more cells,some or all of which may contain one or more sampling arrangements forcollecting a fluid sample, as described in more detail below. The metermay be further configured to display or otherwise provide one or moreresults from the sample analysis. It should be appreciated that someportions of the meter may be reusable, while other portions of the metermay be disposable. For example, in some variations the meter housing isreusable while the cartridge is disposable. In these variations, newcartridges may be inserted into or otherwise engage with a meter housingto conduct a new series of tests. In other variations, both the meterhousing and the cartridge may be disposable.

FIGS. 1A-1D show an illustrative variation of the meters described here.Specifically, the meter may comprise a meter housing (100) and acartridge (102). Specifically, FIGS. 1A and 1B show a front view and abottom perspective view, respectively, of meter housing (100), whileFIG. 1C shows a perspective view of cartridge (102). While shown in FIG.1C as being stored in a sealable pouch (116), it should be appreciatedthat cartridge (102) may be stored in any suitable container, and may beremoved prior to use. FIG. 1D shows a cross-sectional view of meterhousing (100) with cartridge (102) placed inside of meter housing (100).As shown there, meter housing (100) may comprise a door (104) with acartridge-engagement projection (105), a cartridge-receiving chamber(106) or cavity, triggering mechanism (107), display (108), buttons(110), port (112), and tower (114). The meters described here need notinclude each of these features, and it should be appreciated that themeters described here may comprise any combination of these features.Each of these features will be described in more detail below. Meterhousing (100) may further comprise one or more imaging systems (notshown), and internal mechanisms or components (e.g., memory, circuitry,actuators, batteries, vacuum pumps, sensors, combinations thereof, etc.)for operating the meter and/or facilitating a testing procedure.

Door (104) may be opened to reveal cartridge-receiving chamber (106), asshown in FIG. 1B. Cartridge (102) may be placed inside ofcartridge-receiving chamber (106), and door (104) may be closed totemporarily enclose cartridge (102) within the meter housing (100). Whenplaced inside of meter housing, one or more portions of the cartridgemay engage one or more components of the meter housing (100). In somevariations, meter housing (100) may comprise one or more features thatmay facilitate self-alignment of the cartridge (102) as it is placed inthe cartridge-receiving chamber (106), as will be described in moredetail below. In some variations, the cartridge (102) may comprise arecess (not shown). When cartridge (102) is placed inside ofcartridge-receiving chamber (106), a portion of tower (114) may fitwithin or otherwise engage the recess of cartridge (102). Thisengagement may help to hold cartridge (102) in place relative to meterhousing (100). Conversely, in some variations the cartridge (102) maycomprise one or more projections (not shown) that may engage one or morerecesses (not shown) in the cartridge-receiving chamber (106) or otherportion of the meter housing (100). Additionally or alternatively, oneor more magnets may hold the cartridge in place relative to the meterhousing. It should be appreciated that a cartridge need not be placedinside of a meter housing (e.g., via a cartridge-receiving chamber) toengage the meter housing. For example, in some variations, a cartridgemay attach to or otherwise engage one or more external surfaces of ameter housing.

When the door (104) of a meter housing (100) comprises acartridge-engagement projection (105). The cartridge-engagementprojection (105) may press against or otherwise bias the cartridge (102)when a cartridge (102) is placed in a cartridge-receiving chamber (106)and the door (104) is closed. For example, when a portion of a tower(114) engages the cartridge (102), the cartridge-engagement projection(105) may press and hold the cartridge (102) in engagement with thetower (114). This engagement may help account for mechanical tolerancesof the meter. In some variations, the cartridge-engagement projection(105) may be spring-loaded to bias the cartridge (102).

Additionally, cartridge (102) may house or otherwise hold one or moresampling arrangements (130). These sampling arrangements, as will bedescribed in more detail below, may be contained in one or more cells ofthe cartridge, and may comprise one or more components for collecting,transporting, and/or reacting with a fluid sample. For example, in somevariations, the sampling arrangement (130) may comprise a penetrationmember (136) for piecing, penetrating or otherwise puncturing a samplingsite during a testing procedure. In variations where the cartridge (102)comprises a plurality of sampling arrangements, each samplingarrangement may be utilized to conduct a separate test on a differentfluid sample. In variations where cartridge (102) is configured to bedisposable, new cartridges may be swapped in to provide unused (e.g.,unfired) sampling arrangements.

Once the cartridge (102) has been placed in operative engagement withthe meter housing (100), the meter may be configured to perform one ormore testing procedures, during which a fluid sample is collected andanalyzed. Prior to initiating a testing sequence, the meter may first beactivated by one or more of buttons (110) or another suitable switch,lever, pressure sensor, or the like. Activating the meter may comprisepowering up the meter housing (100), or may comprise waking the meterfrom a hibernation mode. It should be appreciated that the meter may beactivated (e.g., powered up or awoken from a hibernation mode) prior toplacement of cartridge (102) in meter housing. In other variations,placement of the cartridge (102) inside of the meter housing (100) mayactivate the meter.

Upon activation of the meter and/or placement of cartridge (102) in themeter housing (100), the meter may be configured to run one or moreprocedures to check the integrity of, index, and/or otherwise obtaininformation from the cartridge (102), as will be described in moredetail below. In some of these procedures, the meter may be configuredto evaluate whether individual sampling arrangements of the cartridge(102) have previously been used, fired, or otherwise actuated(intentionally or inadvertently). In variations where portions of thecartridge are sealed from the external environment, the meter may beconfigured to check the integrity of the seal. Additionally oralternatively, the meter housing (100) may be configured to obtaininformation (e.g., calibration information, expiration dates, etc.)stored on, stored in, or otherwise associated with the cartridge (102).If the meter determines that the cartridge has expired, or all of thesampling arrangements have either been used or otherwise comprised, themeter may be configured to prevent the initiation of a test, and mayadditionally alert the user (e.g., via one or more visual prompts,sounds, tactile stimuli, or other identifiers) to insert a new cartridge(102).

In order to insert a new cartridge, it may be first necessary to removea cartridge that is already housed in a meter housing. A cartridge maybe ejected or removed from the meter housing in any suitable manner. Itshould be appreciated that in some variations, the meter housing (100)may be configured to eject a used cartridge (102) without requiringdirect user contact with the cartridge, which may help to reduce therisk of user exposure to potentially hazardous materials (e.g., usedneedles or lancets). For example, in some variations, the meter housing(100) may comprise one or more ejection buttons (113), that may bedepressed or otherwise activated to eject the cartridge (102) from themeter housing (100) without requiring a user to touch the cartridge(102). In other variations, the cartridge (102) may be configured topassively fall from the cartridge housing when a door (104) of the meterhousing (100) is opened. Examples of illustrative cartridge ejectionmechanisms will be described in more detail below.

After any checking/indexing/information gathering procedures have beencompleted, the meter may enter a ready mode, in which cartridge (102) ispositioned such that an un-fired sampling arrangement is in alignmentwith port (112), as shown in FIG. 1D. At this point, a user may initiatea testing procedure. Alternatively, the alignment of a samplingarrangement with the port (112) may not occur until after the testingprocedure has been initiated. In some instances, the testing proceduremay be initiated by pressing one or more of buttons (110) or activatinganother suitable element (e.g., one or more buttons, switches, levers,sensors, combinations thereof, and the like). In other instances, a usermay activate a testing procedure by placing a sampling site (e.g., oneor more skin surfaces or a fluid-filled container) against port (112),as will be described in more detail below. For example, the port (112)may comprise a moveable contact pad against which a user may press asampling site (e.g., a skin surface), and which may contact a portion ofthe cartridge when a sampling site is applied thereto.

Once a testing procedure has been initiated, the meter may be configuredto activate or otherwise actuate the sampling arrangement (e.g., via atrigger mechanism or the like) to pierce, puncture, or otherwisepenetrate the sampling site. The sampling arrangement may further beconfigured to draw or otherwise collect a fluid sample from the samplingsite. Additionally, vacuum, pressure, and/or heat may be applied to thesampling site before, during, or after the sampling arrangement collectsthe fluid sample. In variations where vacuum is applied to the samplingsite, the amount of vacuum may be varied or otherwise modulated, as willbe described in more detail below. Additionally or alternatively, insome variations the sampling site may be mechanically stimulated usingvibrations, massage, or the like. As the fluid sample is collected, themeter may analyze the fluid sample, as will be described in more detailbelow. Analysis of a fluid sample may include determining theconcentration of one or more target analytes (e.g., glucose) in thefluid sample. In some variations, the meter may be configured todetermine whether the fluid sample collected by a sampling arrangementis a control sample. The meters described here may comprise one or moreimaging systems which may image one or more portions of the samplingarrangement during analysis of the fluid sample. Specific metercomponents, and methods for using these meters, will be described inmore detail below.

Cartridge

As mentioned above, the meters described here may comprise one or morecartridges. Generally, the cartridge may engage, fit within, and/orattach to a meter housing, and may comprise one or more samplingarrangements housed within one or more cartridge cells. As will bedescribed in more detail below, the sampling arrangements may comprisespecific components for obtaining, transporting and/or reacting with afluid sample. Any reactions that occur between sampling arrangement andthe fluid sample may be quantified or measured by one or more portionsof the cartridge or the meter housing (e.g., an imaging system), as willbe described in more detail below. The cartridge may be removable fromthe meter, or may be integrated into the meter. When the cartridge isremovable from the meter, it may or may not be configured to bedisposable. In some variations, one or more portions of the cartridgemay be reusable. For example, a cartridge containing one or more unusedsampling arrangements may be loaded into the cartridge to allow themeter to conduct additional testing procedures.

Any suitable cartridge may be used with the meters described herein. Forexample, in some variations, the meter may comprise one or more of thecartridges described in U.S. patent application Ser. No. 11/529,614,titled “MULTI-SITE BODY FLUID SAMPLING AND ANALYSIS CARTRIDGE,” and Ser.No. 12/222,724, titled “ANALYTE CONCENTRATION DETECTION DEVICES ANDMETHODS,” the contents of each is hereby incorporated by reference inits entirety. FIGS. 2A-2D illustrate one variation of cartridge (200)suitable for use with the meters described herein. Specifically, FIGS.2A and 2B show bottom perspective and cross-sectional views,respectively, of cartridge (200). FIGS. 2C and 2D show a top perspectiveview, and a partial-top perspective view, respectively of cartridge(200). As shown in these figures, cartridge (200) may comprise a housing(202) that may be divided into a plurality of separate cells, such ascells (204). One or more of the cells (e.g., cells (204)) may compriseone or more sampling arrangements (206), such as one or more of thosedescribed in more detail below. Cartridge (200) may comprise a recess(207) extending at least partially through the cartridge housing (202).One or more portions of a meter housing may extend at least partiallythrough the recess (207) to engage the cartridge (200), as will bedescribed in more detail below. Housing may also comprise teeth (209),which may engage a portion of the meter housing (not shown) to helpalign and move the cartridge relative to the meter housing, as will bedescribed in more detail below. Additionally, at least a portion ofcartridge may be sealed, covered, or otherwise masked by one or moresections of covering material (208), as shown in FIG. 2A. Coveringmaterial (208) is not shown in FIGS. 2B-2D so as to allow for betterillustration of the remaining components of the cartridge (200).

While shown in FIG. 2C as being formed from two separate pieces (topsegment (203) and bottom segment (205)), it should be appreciated thathousing (202) may be made from any suitable number of separate pieces(e.g., one, two, three, or four or more). FIG. 2D shows cartridge (200)with a top segment (203) of the housing (202) removed, revealing theplurality of sampling arrangements (206).

While shown in FIGS. 2A-2D as comprising a plurality of samplingarrangements (206), the cartridge may house only a single samplingarrangement (206) if desirable. In these variations, the cartridge maybe configured to run a single testing procedure, at which point thecartridge may be removed and replaced with an unused cartridge, as willbe described in more detail below. In variations where the cartridge(200) comprises a plurality of sampling arrangements, the cartridge maycomprise any suitable number (e.g., two, three four, five, six, seven,eight, nine, ten, eleven, or twelve or more) of sampling arrangements.Different sampling arrangements within the cartridge may comprise thesame elements and the same configuration of elements, or may comprisedifferent elements or different element configurations. For example,some sampling arrangements in a cartridge may be configured to reactwith and allow for the measurement of a first analyte concentration in afluid sample, while other sampling arrangements may be configured toreact with and allow for the measurement of a second analyte. In otherinstances, some sampling arrangements may be actuated or moved by atorsional spring, while other sampling arrangements may be actuated ormoved by a linear spring or leaf spring. Additionally or alternatively,one or more sampling arrangements may be actuated by anelectromechanical or pneumatic actuator.

Additionally, while each sampling arrangement (206) shown in FIGS. 2A-2Dis housed in a separate cell (204), it should be appreciated that insome instances multiple sampling arrangements may be placed in a singlecell. For example, in some variations it may be desirable to obtain andanalyze two or more fluid samples simultaneously. Furthermore, somecells may not house or otherwise comprise a sampling arrangement. Forexample, one or more cells may be configured to hold, house, orotherwise contain one or more memory units, an optical reference (e.g.,one or more colored members), a desiccant, a sensor for determiningexposure to the external environment, or the like. While shown in FIGS.2A-2D as being substantially cylindrical, the cartridges described heremay have any suitable shape. In some variations, the cartridge may bebox- or disc-shaped.

The cells of the cartridge may comprise one or more walls. For example,as shown in FIG. 2B, cell (204) may comprise outer perimeter wall (210)in an outer perimeter surface (211) of the cartridge, inner perimeterwall (212) in a perimeter surface (213) of recess (207), top wall (216)in a top surface (217) of the cartridge, bottom wall (214) in a bottomsurface (215) of the cartridge, and side walls (218) separating adjacentcells (204). In some variations, one or more of the walls may includeone or more apertures or holes therethrough, which may allow access tothe interior of the cartridge cell (204) (or may allow one or moreelements of the sampling arrangement to exit the meter). For example, asshown in FIGS. 2A-2C, the outer perimeter wall (210) of each cell (204)may comprise an aperture (220). One or more portions of the samplingarrangement (206) may pass through aperture (220) during a testingprocedure. Additionally or alternatively, the bottom wall (214) of acell (204) may comprise one or more apertures, such as aperture (222)shown in FIG. 2B. In some variations, a portion of one or more vacuumsources or trigger mechanisms (not shown) may be advanced into a cell(204) through aperture (222) to apply vacuum pressure to the cell and/orto engage the sampling arrangement. Additionally or alternatively, thetop wall (216) of a cell may comprise one or more apertures, such asaperture (224) shown in FIG. 2C. In some variations, one or more sidewalls (218) of a cell (204) may comprise an aperture (not shown), whichmay allow for gaseous communication between adjacent cells.

As mentioned above, one or more desiccant pieces may be packaged withand/or inside of the cartridge. The desiccant may help absorb moistureinside of the cartridge, which may help increase the shelf life of thecartridge by minimizing interaction between any moisture and one or morereagents or other chemicals housed in the cartridge. In some variations,one or more portions of the cartridge housing may be made from adesiccant material. In variations where the cartridge comprises aplurality of cells, one or more pieces of desiccant may be placed in oneor more of the cartridge cells. In variations where one or morecartridge cells comprise a sampling arrangement, a piece of desiccantmay be placed in the same cell as a sampling arrangement. In othervariations, a piece of desiccant may be placed in a cell that does notcomprise a sampling arrangement. In some of these variations, one ormore apertures may connect a cell that comprises a sampling arrangementwith a cell that holds a piece of desiccant, thereby providing gaseouscoupling between the desiccant and the sampling arrangement. Forexample, in the variation of cartridge (200) described above in respectto FIGS. 2A-2D, one or more desiccant pieces (230) may be placed insideof a cartridge cell (232) via aperture (224). An aperture (not shown)may gaseously couple cell (232) and an adjoining cell (204) containing asampling arrangement (206), which may allow the one or more desiccantpieces (230) to draw moisture from cell (204) into cell (232), where ismay be absorbed by the one or more desiccant pieces (230).

In some variations each desiccant-containing cell (232) may be gaseouslycoupled to a single sampling arrangement-containing cell (204). In thesevariations, exposure of a single sampling arrangement-containing cell(204) to the environment (e.g., during a testing procedure, as will bedescribed in more detail below) may allow other cells (204) to remainisolated from the environment. In other variations, adesiccant-containing cell (232) may be coupled to multiple samplingarrangement-containing cells (204).

In some variations, one or more portions of a cell wall may betransparent, which may allow the portion of the cell to act as a viewingwindow. These viewing windows may be made from any suitable transparentmaterial or materials (e.g., glass, plastic, etc.), and may allow forvisualization of the interior of the cartridge by an imaging system,such as those described in more detail below. In some variations, only aportion of a wall may be made from a transparent material. In othervariations, an entire wall may be made from a transparent material ormaterials, and thus the entire wall may act as a viewing window. Anysuitable cell wall or walls may act as a viewing window (e.g., a topwall, a bottom wall, and/or a perimeter wall). In other variations, oneor more apertures in a cell wall may allow for visualization of theinterior of the cartridge by an imaging system. In variations where anaperture is covered by one or more covering materials (as describedimmediately below), it may be necessary to first remove the coveringmaterial from the aperture for it to be used as a viewing window. Inother variations, a covering material may be transparent, which mayallow for visualization through the covering material.

Although shown in FIG. 2A above as comprising one or more sections of acovering material (208), cartridge (200) need not. In variations that docomprise a covering material, the covering material may be used to coverone or more surfaces and/or apertures of the cartridge housing (200).When the covering material covers the apertures of a cell, the coveringmaterial may act to form a temporary barrier between the externalenvironment and the cartridge interior, thereby temporarily sealing thecartridge cell. By sealing the individual cells from the externalenvironment, covering material may help prevent or minimize the risk ofexternal stimuli (e.g., gases, moisture, etc.) affecting the shelf lifeof or contaminating one or more portions of the sampling arrangement.Additionally, the covering material may be used to trap one or moregases (e.g., a nitrogen-based gas or mixture) inside of the cartridgecells, which may increase the shelf life of the sealed cartridge. Thecovering material may at least temporarily cover any surfaces and/orapertures of the cartridge. For example, in the variation of cartridge(200) shown in FIG. 2A, covering material (208) may cover the topsurface (217), outer perimeter surface (211) and bottom surface (215) ofthe cartridge, including apertures (220), (222), and (224) in thesesurfaces. In this variation, at least a portion of the transparent innerperimeter walls (212) may remain uncovered to allow visualizationtherethrough. Alternatively, the transparent inner perimeter walls (212)may be covered by a transparent covering material (not shown).

Covering material (208) may be made from any suitable material ormaterials (e.g., a metal foil such as aluminum, steel, or the like, aplastic membrane such as ethyl vinyl acetate, polyethylene, polyester,or the like, combinations or composites thereof, and the like), and maybe attached to a cartridge in any suitable manner (e.g., one or moreadhesives, such as a pressure-sensitive or heat-sensitive adhesive). Thecovering material may be made from a single or multiple layers ofmaterial. In variations in which the covering material is amulti-layered covering, the various layers may be made from differentmaterials, but need not be. In some variations, one or more portions ofthe covering material may be substantially opaque or otherwiseimpervious to light. In these variations, the light-blocking coveringmaterial may help the meter assess the integrity of the seal provided bythe covering material, as will be described in more detail below.Additionally, in some variations a single piece of covering material maybe used to cover the cartridge. In other variations, different pieces ofcovering material may be used to cover different surfaces (or portionsthereof) of the cartridge. For example, in some variations a first pieceof covering material may cover a bottom surface, a second piece maycover an outer perimeter surface, and a third piece may cover a topsurface of the cartridge. In some of these variations, the differentpieces of covering material may be the same material or may be differentmaterials. For example, in some variations a first piece of coveringmaterial covering a bottom surface of the cartridge may include a firstlayer comprising low density polyethylene (LDPE) and a second layercomprising a metal foil (e.g., aluminum foil), while a second piece ofcovering material covering an outer perimeter surface may include afirst layer comprising ethyl vinyl acetate and a second layer comprisinga metal foil (e.g., aluminum foil). In still other variations, differentpieces of covering material may seal different cartridges.

During operation of the meter, one or more portions of the coveringmaterial may be punctured, moved, or otherwise removed to facilitatesampling and/or analysis of a fluid sample. For example, removal of thecovering material overlying an aperture may present an unimpeded pathfor a portion of a sampling arrangement to pass through the aperture. Inthe variation of cartridge (200) shown in FIG. 2A, a portion of coveringmaterial (208) overlying aperture (220) has been removed/punctured toprovide access to the interior of cartridge (204). In variations where aportion of the covering material is removed to provide access tointerior of a cartridge, the covering material may be configured to aidin removal. For example, in some variations, the covering material maycomprise a first layer comprising ethyl vinyl acetate and a second layercomprising a metal foil (e.g., aluminum). In these variations, the ethylvinyl acetate may facilitate breaking or rupturing of the coveringmaterial as it is punctured or otherwise removed (e.g., via a punch, aswill be described in more detail below). In other instances, a portionof a sampling arrangement may pierce or puncture the covering materialupon activation of the sampling arrangement.

In still other instances, one or more vacuum tubes or triggeringmechanisms may puncture the covering material to gain access to theinterior of a cell. In some of these variations, the covering materialmay comprise one or more materials which may act to form a seal around avacuum tube or a triggering mechanism when the tube or mechanismpunctures the covering material. For example, in some variations, one ormore apertures may be covered by a covering material that may comprise afirst layer comprising low density polyethylene (LDPE) and a secondlayer comprising a metal foil (e.g., aluminum foil). In thesevariations, the elastic nature of the LDPE may seal around a vacuum tubeor triggering mechanism as it punctures the covering material.

In some variations, a cartridge may be configured to carry informationrelating to the cartridge or one of the components thereof. Thecartridges may carry any suitable information (e.g., calibration codes,batch information, expiration information, and the like) in any suitablemanner. For example, in the variation of cartridge (200) shown in FIG.2A, cartridge (200) may comprise one or more barcodes (226). In thesevariations, the meter housing (not shown) may comprise one or morebarcode scanners/readers. In variations where the cartridges arecylindrical or have an otherwise rounded cross-sectional area, thecartridge may be rotated to facilitate reading the barcode. In otherinstances, the meter housing may be configured to move the cartridgeinto a position where the barcode may be read. The cartridge maycomprise any suitable number of barcodes (e.g., zero, one, two, three,or four or more barcodes).

While shown in FIG. 2A as comprising a barcode (226), cartridge (200)need not. In some variations, the cartridge may comprise one or morememory chips or cards, which may convey information to the meterhousing, such as, for example, through RF transmission, opticalcommunication, or via direct electrical communication. In thesevariations, the meter housing may be further configured to upload/inputdata or other information into the cartridge memory. For example, themeter housing may upload date information in the cartridge relating tothe first use of said cartridge. In this way, if the cartridge is placedin a different meter housing, the new meter housing may download thefirst usage date of the cartridge. This may be of particular relevancein instances where a cartridge has a limited shelf life after its firstusage, or after removal from a sterile packaging. In other variations, aseparate memory card or chip may be packaged and/or provided with thecartridge. This memory card or chip may be inserted into a portion ofthe meter to convey information to the meter. In still other variations,a user or physician may manually enter information regarding thecartridge into the meter.

While cartridge (200) discussed above in relation to FIGS. 2A-2Dcomprises multiple sampling arrangements, it should be appreciated thata cartridge may comprise a single sampling arrangement. For example,FIGS. 13A-13C depict an illustrative variation of a cartridge (1300)comprising a single sampling arrangement (1302). FIGS. 13A, 13B, and 13Cshow a side, cross-section view of a single sampling arrangement (1302)in a loaded position, an extended position, and a rest position,respectively. While shown in FIG. 13A as having a covering material(1384), the cartridge need not. In variations of cartridges that docomprise a covering material (1384), one or more portions of thecovering material (1384) may be removed and/or punctured duringoperation of the device. Cartridge (1302) may be loaded into acartridge-receiving chamber of a meter housing (not shown), such as oneor more of the meter housings described hereinthroughout. When placedinside of a meter housing, the cartridge (1302) may be positionedrelative to an imaging system (1380) such that an interior of thecartridge (1302) may be viewed through a transparent window (1382), asdescribed in more detail below.

While sampling arrangement (1302) is shown in FIGS. 13A-13C as having ahub (1390), penetration member (1388), and linear spring (1386), itshould be appreciated that sampling arrangement (1302) may have anyelements or combinations of elements as will be described in more detailbelow. When cartridge (1302) is in place within the meter housing, themeter may comprise one or more triggering mechanisms that may activatesampling arrangement (1302). In the variation shown in FIGS. 13A-13C,one or more trigger pins (1320) may press against one or more latches(1322) of hub (1390) to actuate the sampling arrangement (1302), whichmay move from a loaded position as shown in FIG. 13A to an extendedposition as shown in FIG. 13B, and eventually to a rest position in FIG.13C. The sampling arrangement (1302) may be configured to collect afluid sample when in the extended and/or rest positions, and the fluidsample may be analyzed (e.g., visualization of the sampling arrangement(1302) by the imaging system (1380) before, during, and/or aftercollection of the fluid sample may assist in analysis of the fluidsample). Following collection and/or analysis of the fluid sample, thecartridge (1302) may be removed from the meter housing, and a freshcartridge with an unused sampling arrangement may be placed in the meterhousing.

It should be appreciated that the cartridges suitable for use with themeters described here may comprise any combination of elements orfeatures described above, and may comprise any sampling arrangements orcombination of sampling arrangements described below.

Sampling Arrangements

The cartridges described above generally comprise one or more samplingarrangements for obtaining, transferring, and/or reacting with one ormore fluid samples. Any suitable sampling arrangements may be used withthe meters described here, such as those described in U.S. patentapplication Ser. No. 11/529,614, titled “MULTI-SITE BODY FLUID SAMPLINGAND ANALYSIS CARTRIDGE,” the content of which is hereby incorporated byreference in its entirety. Generally, the sampling arrangements maycomprise one or more penetration members for piercing, puncturing orotherwise penetrating a sampling site (e.g., a skin surface) and/orcollecting a fluid sample from the sampling site. The samplingarrangement may further comprise a hub or other structure for moving thepenetration member relative to the cartridge. Additionally, the samplingarrangement may comprise a quantification member, which may react withthe fluid sample to produce a measurable response (e.g., anelectrochemical or photometric response) that may be indicative of oneor more properties of the fluid sample.

FIGS. 3A-3E illustrate a variation of a sampling arrangement (300)suitable for use with the meters described here. FIGS. 3A and 3B show aside view and an exploded perspective view, respectively, of samplingarrangement (300). Shown there are hub (302), needle (304), standoff(305), pad (306), cap (308), and torsional spring (310). Hub (302) maycomprise latch (312), pivot bars (314), and a micropatterned surface(316). In this variation, hub (302) may hold needle (304) such that aninterior bore (317) of the needle is in fluid communication withmicropatterned surface (316). Pad (306) or another quantification membermay be placed on micropatterned surface (316), and cap (308) may beplaced at least partially over pad (306) to hold the pad (306) in placeagainst the micropatterned surface (316). Cap (308) may comprise anaperture (318) or other viewing window through which the pad (306) maybe viewed.

In the variation of sampling arrangement (300) described immediatelyabove, hub (302) may be configured to rotate relative to a cartridgecell (322). FIGS. 3C-3E illustrate a method by which samplingarrangement may rotate relative to a cartridge cell (322). Whenpositioned inside of cartridge cell (322), pivot bars (314) may engageone or more portions of the cell (322) such that the pivot bars (314)may rotate relative to the cartridge, but are otherwise held in place.As such, pivot bars (314) may act as a pivot point around which the restof the sampling arrangement (300) may rotate. Indeed, the samplingarrangement (300) may rotate between a cocked/pre-fired position, anextended position, and a resting position, as shown in FIGS. 3C-3E,respectively. It should be appreciated that an imaging system of themeter may visualize or otherwise image one or more portions of thesampling arrangement (300) (e.g., pad (306)) when the samplingarrangement is in a stationary position, or as the sampling arrangement(300) moves between some or all of these positions.

When in a pre-fired position, the torsional spring (310) may bepositioned such that it is compressed/wound, as shown in FIG. 3C. Inthis way, the spring may store energy that may later be used to drivethe sampling arrangement (312). It should be appreciated that in someinstances a spring may be stretched or bent instead of compressed. Alatch (312) or similar structure may engage a portion of the cell (322),thereby temporarily locking the sampling arrangement (300) in place.During a testing procedure, a trigger mechanism or similar mechanism, aswill be described in more detail below, may disengage latch (312) orotherwise release the sampling arrangement so that it is free to move.Torsional spring (310) may then decompress/unwind to rotate hub (302)around pivot bars (304). The hub may then rotate hub forward around thepivot point provided by the pivot bars (304) such that the samplingarrangement (300) enters an extended position, as illustrated in FIG.3D. In this position, the sampling arrangement may be positioned suchthat a needle (304) or other penetration member of the arrangement maypierce, penetrate or otherwise puncture a sampling site (not shown) tocollect a fluid sample (not shown). In some instances, needle (304) mayextend through an aperture (326) of cell (322) when in an extendedposition, but need not. Hub (302) may rotate back and forthharmonically, eventually coming to rest at a resting position, as shownin FIG. 3E. Because pivot bars (314) act as a pivot point around whichthe sampling arrangement may rotate, a needle (304) may follow a fixedpath during rotation. Additionally, the sampling arrangement and/orcartridge may comprise one or more protrusions or other elements thatmay help limit return rotation of the hub (302), as will be described inmore detail below. As shown in FIG. 3E, the needle (304) may be entirelycontained within the cartridge cell (322) when in the resting position,which may help minimize the risk of accidental needle sticks following atesting procedure.

While sampling arrangement (300) is shown in FIGS. 3A-3E as beingconfigured to rotate relative to the cartridge, it should be appreciatedthat the sampling arrangements described here may be configured to movein any suitable manner relative to the cartridge. For example, in somevariations, a sampling arrangement may be configured to slide orotherwise move in a linear fashion relative to the cell. In some ofthese variations, a portion of the sampling arrangement (e.g., a hub)may comprise one or more protrusions (e.g., a protrusion similar topivot bars (314) described above), which may be configured to slide ormove within one or more tracks in the cartridge cell. The tracks may bestraight to provide a linear path for the sampling arrangements, or maybe curved/zig-zagged to provide for multi-dimensional movement of thehub. In some of these variations, the protrusions may have anon-circular or non-rounded cross-section profile (e.g., rectangular,square, or the like), which may allow the protrusion to slide within atrack but may prevent rotation of the protrusion relative to the track.Additionally or alternatively, the sampling arrangement may comprise twoor more protrusions disposed in a single track, which may also help toprevent rotation of the sampling arrangement relative to the cartridge.Conversely, it should be appreciated that the cartridge may comprise oneor more protrusions/pivot bars, and the sampling arrangements maycomprise one or more tracks which may slide along and/or rotate aroundthe protrusions.

While sampling arrangement (300) is shown in FIGS. 3A-3E as comprising atorsional spring (310), it should be appreciated that the samplingarrangement (300) may be moved by any suitable mechanism during atesting procedure. For example, in some variations the samplingarrangements may comprise one or more springs (e.g., a torsional spring,a linear spring, a leaf spring, a conical spring or the like). In thesevariations, the springs may be held in a compressed or stretchedconfiguration, the stored energy from which may act to slide, rotate, orotherwise move one or more portions of the sampling arrangement whenreleased. In other variations, one or more one or more actuators mayslide, rotate, or otherwise move the sampling arrangement relative tothe cartridge. For example, in some variations a mechanically-driven armmay temporarily engage a portion of the sampling arrangement (e.g., thehub) to slide, rotate, or otherwise move the sampling arrangement.

As mentioned above, the sampling arrangements described here maycomprise one or more penetration members for facilitating collection ofa fluid sample. The penetration member may be any suitable structurecapable of piercing, puncturing, or otherwise penetrating a samplingsurface. For example, in some variations the penetration member maycomprise a hollow needle or microneedle. The needle may have anysuitable outer diameter (e.g., about 300-600 μm, about 500 μm, etc.) orgauge (20-25, 26-36, etc.), and any suitable inner diameter (e.g., about25-250 μm). In some variations, the hollow needle may be configured tocollect and transport a fluid sample through the bore of the needle. Insome instances, the diameter of the bore is sufficiently small to drawfluid into the needle by capillary action. In other variations, thepenetration member may comprise a solid lancet. In these variations, thelancet may comprise one or more channels/microchannels on a surfacethereof for transporting a fluid along a surface thereof. Thepenetration members described here may be made of any suitable materialor combination of materials (e.g., one or more metals, plastics,glasses, or the like), and may additionally comprise one or morecoatings (e.g., polydimehtylsiloxane, Silwet™, or the like) and/orsurface texturing to help promote fluid flow relative to the penetrationmember. In some variations, one or more coatings may comprise heparin oranother anticoagulant to help prevent blood from clotting in or on thepenetration member.

As mentioned above, the sampling arrangement may comprise one or morestandoffs, such as standoff (305) shown in FIGS. 3A-3E. The standoff maybe attached to and/or at least partially circumscribe a portion of thepenetration member (e.g., a needle or solid lancet). A standoff mayserve a number of useful functions. In some variations, the standoff mayact to help block light from entering a cartridge cell. For example, inthe variation of sampling arrangement (300) described above, whensampling arrangement (300) is placed in an extended position or aresting position (as shown in FIGS. 3D and 3E respectively), thestandoff (305) may at least partially block or cover aperture (326). Inthis way, standoff (305) may substantially prevent light from enteringthe cartridge cell, which may help to minimize stray light from enteringthe optical system of the meter. In some variations, standoff (305) maybe made from a matte or light-absorbing material that helps preventlight from reflecting off standoff (305) into the cartridge.

In other instances, the standoff (305) may aid in collection of a fluidsample. Specifically, in some variations at least a portion of thestandoff (305) may be concave. During a testing procedure, a user mayapply a portion of a fluid sample to the concave surface of the standoff(305) (e.g., by milking a drop of blood onto the standoff). The fluidmay naturally settle to the bottom of the concave surface, where it mayenter a lumen (not shown) of needle (304). The standoff may furthercomprise one or more grooves or channels, and/or one or more hydrophobiccoatings to help direct blood toward needle (304)

In still other instances, the standoff (305) may affect or control thedepth and/or rate of penetration of a sampling site during a testingprocedure. As the penetration member pierces a sampling site during atesting procedure, the standoff may engage the sampling site to preventfurther advancement of the penetration member. It should be appreciatedthat in some instances, the depth of penetration will be naturallycontrolled and/or limited by the movement path of the samplingarrangement. In some variations, the standoff may act to limit thepenetration depth of the penetration member. In some of thesevariations, the standoff may be made of a compressible material, whichmay compress against skin during penetration. This compression may helpslow the penetration member as it penetrates a sampling site, which mayhelp to reduce pain associated with the penetration of the penetrationmember. Additionally, energy stored in the compressed standoff may pushagainst the sampling site, and may increase the speed at which thepenetration member exits tissue. Additionally or alternatively, thestandoff may be slidable relative to the penetration member. In thesevariations, the standoff may come into contact with the skin duringpenetration, which may cause the standoff to slide relative to thepenetration member. One or more frictional forces that may result fromthe relative movement between the standoff and the penetration membermay act to limit or resist forward movement of the penetration member.It should also be appreciated that contact between the standoff and theskin may stimulate a larger area of pressure-sensing neurons, which mayinhibit the transmission of pain signals from pain-sensing neurons,thereby reducing pain associated with penetration.

In variations where a spring is configured to rotate the samplingarrangement relative to a cartridge, one or more portions of thesampling arrangement (e.g., the hub) and/or cartridge may be configuredto limit the rotation of the sampling arrangement. In some of thesevariations, one or more portions of the sampling arrangement and/orcartridge may be configured to limit forward rotation of the samplingarrangement. In variations in which a sampling arrangement comprises astandoff, the standoff may help to limit and/or control the forwardrotation of the hub, as described immediately above. In othervariations, one or more portions of the hub may interact with a portionof the cartridge to limit and/or control forward rotation of the hub.Additionally or alternatively, in other variations, one or more portionsof the sampling arrangement and/or the cartridge may prevent rearwardrotation of the sampling arrangement. For example, in some variations, asampling arrangement may comprise one or more stops that may interactwith one or more protrusions or other portions of a cartridge cell toprevent rearward rotation beyond the point of interaction. Specifically,when a sampling arrangement is in the cocked position, a stop may bendor flex protrusion away from an initial configuration. When fired, thestops may temporarily disengage the protrusion, which may straighten orotherwise reconfigure to enter some or all of the space previouslyoccupied by the stops. The protrusion may then block a portion of thereturn path of stops, thereby limiting rearward rotation. Additionallyor alternatively, one or more of the stops may be bent or flexed when asampling arrangement is in a cocked position, and may straighten afterfiring. Similarly, the return path of the unbent stops may be blocked bythe cartridge protrusion to prevent rearward rotation. Although thesampling arrangement may be configured to have a limited range ofrotation, the sampling arrangement may be configured to stop at aresting position at one of the rotational limits, or between therotational limits (e.g., such that the penetration member comes to restin or directly over the puncture wound. It should also be appreciatedthat in variations where a sampling arrangement is moved in a lineardirection, the sampling arrangement and/or cartridge may be configuredto limit and/or control this linear movement.

In some variations, the sampling arrangement may be configured totransfer the fluid sample from one portion of the sampling arrangementto another portion of the sampling arrangement. For example, in thevariation of sampling arrangement (300) described above, a fluid samplecaptured by needle (304) may pass through a bore of the needle (e.g., bycapillary action) to a micropatterned surface (316) of the hub (302).This surface (316) may comprise one or more grooves, channels, and orfluid pathways for drawing the fluid sample from the needle bore andspreading it across surface (316). These surfaces may help to providequick and even wetting of a quantification member (e.g., pad (306)). Forexample, in some variations the sampling arrangement comprises areagent/assay pad that is configured to react with the fluid sample. Insome of these variations, the rate at which the fluid sample spreadsacross the pad may be slow relative to the reaction rate between thefluid sample and the reagent(s). As such, the reaction at one point of apad may be complete before blood may reach another portion of the pad.In some instances, it may be desirable for the fluid sample to be spreadacross the reagent quickly, so as to allow the reaction to occur at asimilar time in different portions of the pad. This may be desirable ininstances where analysis of a fluid sample comprises measuring a rate ofreaction between the fluid sample and the pad. A micropatterned hubsurface may help to spread the fluid sample across the surface of aquantification member more quickly. In some variations (as will bedescribed in more detail below), the micropatterned hub surface may beconfigured to spread fluid across the surface prior to contacting aquantification member. In some of these variations, the fluid sample maycontact different portions of the reagent pad simultaneously. In othersof these variations, the fluid sample may directionally wet the reagentpad (e.g., from one side of a quantification member to a different sideof a quantification member).

As mentioned above, the surface may comprise one or more grooves,channels, and or patterned fluid pathways for drawing the fluid samplefrom the needle bore and spreading it across the surface. These fluidpathways may provide less resistance to fluid flow, and thus the fluidmay travel along these paths, where they may be absorbed by differentportions of the pad. Additionally, depending on the size and spacing,the fluid pathways may be configured to actively draw fluid by capillaryaction, which may increase the speed or degree to which the fluid isdrawn from the needle. The patterned surface may comprise any suitableconfiguration. In some variations, the surface may comprise one or moregrooves or channels, such as those described in U.S. patent applicationSer. No. 11/239,123, titled “DEVICES AND METHODS FOR FACILITATING FLUIDTRANSPORT,” the content of which is hereby incorporated by reference inits entirety.

FIG. 4 illustrates one variation of a sampling arrangement (400)comprising a hub (401) having a patterned surface. As shown there, hub(401) may comprise a lower surface (402), an upper surface (404), aplurality of posts (406) extending from the lower surface (402), and achannel (407) in the upper surface (404). When a quantification member(e.g., a reagent pad) is placed on hub (401), the quantification member(not shown) may rest on the upper surface (404) and/or the tops of posts(406). The posts (406) may be positioned such that spacing between theposts creates a capillary action that draws fluid from a fluid source(408) (e.g., the bore of a needle) from an inlet (410) and spreads thefluid across the lower surface (402). For example, in some variationsthe spacing between adjacent posts may be between about 0.002 and about0.005 inches). The capillary action created by the posts creates aplurality of flow paths, and because these fluid flow paths areinterconnected, blocking the space between two adjacent posts (406)(e.g., with the pad or other debris) may not substantially alter theability of hub (401) to wick the fluid, as the sample may take one ormore alternate paths to reach the same destination.

In some variations, the patterned surface may be configured to draw acertain amount of fluid into the patterned surface prior to contactingthe fluid. For example, in the variation of patterned surface of hub(401) shown in FIG. 4, posts (402) may be of a sufficient height (e.g.,about 0.005 inches) to allow fluid to spread across the lower surface(402) without contacting a quantification member (e.g., a reagent pad).Once the fluid sample has spread across the lower surface (402), thefluid level may rise until it reaches the level of the quantificationmember. At this point, the fluid sample may contact different portionsof the quantification member substantially simultaneously, which mayresult in a more consistent and easily-measured reaction. Additionally,in some variations, lower surface (402) may be configured to collect acertain volume of fluid (e.g., an amount sufficient to complete areaction with the quantification member) before the fluid contacts thequantification member. If an insufficient sample size is collected,fluid will not reach the quantification member (and thus no reactionwill occur), at which point the meter may be configured to alert theuser to apply additional fluid to the sampling arrangement.

As shown in FIG. 4, the fluid source (408) may be centrally positionedrelative to the lower surface (402). In these variations, the fluid maybe configured to spread out in a radial manner. In other variations, thefluid source may be located toward one end of the surface, and may beconfigured to draw fluid directionally away from the fluid source. Thepatterns described above may be formed in any suitable manner, such as,for example, molding, laser ablation, electrode-discharge machining,etching, or another suitable micro-machining technique. Additionally,the micropatterned surface may comprise one or more coatings, such as,for example, a heparin coating, a surfactant coating, a wetting agent,combinations thereof, or the like.

When a quantification member is placed over a patterned surface, gas maybe trapped under the quantification member such that it is containedwithin the flow paths of the patterned surface. As a fluid sample isintroduced to the patterned surface via a fluid source (e.g., the boreof a needle, as describe above), this trapped gas may impede thecapillary action of otherwise affect the fluid flow along one or moreflow paths of the patterned surface, which may further affect theability of a fluid sample to reach and react with the quantificationmember. Accordingly, in some variations of the devices described here,one or more portions of the pattern surface may be fluidly connected toone or more vents or gas-collection regions. For example, in thevariation of hub (401) described above in relation to FIG. 4, channel(407) in the upper surface (404) provide a flow path into which trappedgas may be pushed as fluid spreads across the lower surface (402). Insome of these variations, gas may be able to pass through channel (407)and out of the sampling arrangement (400). For example, in somevariations when a cap (not shown) is placed over the quantificationmember to hold it in place, the cap may be configured such that gas mayflow from the patterned surface, through the channel, and past the cap(e.g., through one or more channels or holes in the cap, or through aspace between the hub and the cap). In other variations, gas may not beable to travel past the cap, and thus gas may be collected in channel(407).

It should be appreciated that while shown in FIG. 4 as having a singlechannel (407), the hub (401) may comprise any suitable number ofchannels (e.g., zero, two, three, or four or more). Variations withmultiple channels may find particular utility in instances where one ormore channels becomes clogged by debris or is otherwise blocked suchthat gas cannot be collected therein and/or flow therethrough.Additionally, while shown in FIG. 4 as having one fluid inlet (410)connected to the fluid source (408), the hub (401) may comprise anysuitable number of inlets

FIGS. 22A and 22B depict a perspective view and a top view,respectively, of a portion of a variation of a sampling arrangement(2200) comprising a hub (2202). As shown there, hub (2202) may comprisea patterned surface having a lower surface (2201), an upper surface(2203), and comprising a plurality of posts (2204), first (2206) andsecond (2208) fluid inlets connected by flow diverters (2210), andchannels (2212). The first (2206) and second (2208) inlets and flowdiverters (2210) may surround a bore (2214). The bore (2214) may befluidly connected to a skin-penetration member, such that a fluid samplecollected by the skin-penetration member may be delivered to the bore(2214). The flow diverters (2210) may be constructed and positioned suchthat the diameter of the bore increases between the lower surface (2201)and upper surface (2203). As the diameter of the bore increases, thecapillary forces created by the bore (2214) decrease, which may promotethe lateral spread of fluid. By promoting lateral spread of fluid, thehub may be configured to collect a certain amount of fluid prior to thefluid level reaching a quantification member (such as a reagent pad).Similarly, the first and second fluid inlets may get wider between thelower surface (2201) and the upper surface (2203), which may alsopromote the lateral spread of fluid. As described in more detail above,the posts (2204) may be positioned relative to the first (2206) andsecond (2208) fluid inlets to provide capillary flow around the posts(2204), such as described in more detail above. In some variations, theposts (2204) may decrease in diameter between the lower surface (2201)and upper surface (2203) which may promote lateral flow as describedimmediately above.

FIGS. 17A and 17B depict a perspective view and a top view,respectively, of a portion of another variation of a samplingarrangement (1700) comprising a hub (1702). As shown there, hub (1702)may comprise an upper surface (1704), a bore (1706), a plurality offluid channels (1708) and flow diverters (1701). As shown there, eachfluid channel (1708) may be positioned between two adjacent flowdiverters (1701) and may include a ramped surface extending between thebore (1706) and the upper surface (1704). The fluid channels (1708) mayprovide capillary forces to draw fluid from the bore (1706) and deliverit to a quantification member (e.g., a reagent pad) that can bepositioned over the fluid channels (1708) and flow diverters (1701) andrest at least partially on the upper surface (1704). The fluid channels(1708) may increase in width between the bore (1706) and the uppersurface (1704) (as the fluid channel (1708) becomes shallower). As thewidth of the channel (1708) increases, the capillary forces provided bythe channel (1708) may decrease. This may encourage each of the fluidchannels (1708) to fill equally, which may result in a more uniformdelivery of fluid to the quantification member.

In the variation of hub (1702) shown in FIGS. 17A and 17B, the flowdiverters (1701) may include a first plurality of flow diverters withupper surfaces (1710) that are parallel with the upper surface (1704) ofthe hub (1702) and a second plurality of flow diverters with uppersurfaces (1710) that are angled downward toward the bore (1706). Thequantification member (not shown) may rest on the upper surfaces (1710)of the first plurality of flow diverters (which may help prevent thequantification member from bowing in towards bore (1706), while thesecond plurality of flow diverters may allow fluid to reach a largerarea of the reagent pad. It should be appreciated, however, that in somevariations the upper surfaces (1710) of each of the flow diverters(1701) may be parallel to the upper surface (1704) of the hub (1702),while in other variations the upper surfaces (1710) of each of the flowdiverters (1701) may be angled toward the bore (1706).

As mentioned above, the sampling arrangements described here maycomprise one or more quantification members for reacting with a fluidsample to provide a measurable result. The quantification member may beconfigured for electrochemical or photochemical reactions with the fluidsamples. For example, in some variations, the sampling arrangement maycomprise one or more reagent/assay pads, such as pad (306) depicted inFIG. 3B above. These pads may be made from one or more absorbentmaterials (e.g., nitrocellulose), which may contain one or more chemicalreagents for reacting with the fluid sample. These chemical reagents mayreact with the fluid sample to produce one or more measurable parameters(e.g., a color change, an electrochemical response, or the like), whichmay be detected and/or measured by one or more portions of the meter. Invariations where the quantification member is configured to produce aphotometric response, the quantification member may be imaged using oneor more imaging systems, as will be described in more detail below. Invariations where the quantification member is configured to produce anelectrochemical response, the sampling arrangement may comprise one ormore electrodes for measuring or otherwise quantifying theelectrochemical response. Additionally, it should be appreciated thatany suitable photometric or electrochemical quantification member ormembers may be used with the sampling arrangements described here.

As mentioned briefly above, a cap or other holding structure may be usedto hold the quantification member in place relative to the hub. Forexample, in sampling arrangement (300) described above in relation toFIGS. 3A-3E, cap (308) may hold pad (306) against micropatterned surface(316) of hub (302). As shown there, the cap (308) may comprise anaperture (318) through which the pad (306) may be viewed using one ormore imaging systems, such as will be described in more detail below.This may provide particular utility in instances where is may bedesirable to optically image a quantification member. While shown inFIG. 3B as having an aperture (318), the cap (308) may additionally oralternatively comprise one or more viewing windows made from atransparent material.

The caps described herein may engage a hub in any suitable manner. Insome variations, the cap may be integrally formed as a part of a hub(e.g., may be formed as a flip-top lid associated with the hub). Inother variations, the cap may be press fitted against a hub. In stillother variations, cap may be attached to hub via one or more latches orother attachment mechanisms. In some variations, when a cap is attachedto a hub, the cap may be configured to compress at least a portion of aquantification member between the cap and the hub. This compression ofthe quantification member may affect the member's ability to draw in orotherwise react with a fluid sample. In variations where the capcomprises a viewing window, the portion of the quantification memberoverlaid by the viewing window may not be compressed, and thus thatportion of the quantification member may not be affected by compression.In this way, compression of an unviewed portion or portions of aquantification member may limit the fluid absorbed by the unviewedportion or portions. In variations where the cap is press fit againstthe hub, the cap may be adjustably pressed against the hub to adjustablycompress the quantification member.

In some variations where the sampling arrangement is configured to beviewed by an imaging system, as will be described below, the cap maycomprise one or more light-altering features for deflecting, absorbingor capturing stray light (e.g., stray light generated by the lightsource, or stray light reflected by a quantification member). FIGS.5A-5C illustrate different variations of caps suitable for use with thesampling arrangements described here. As shown in FIG. 5A, cap (500) maycomprise a tapered recess (502) surrounding aperture (504). The taperedrecess (502) may act to deflect or catch stray light. While shown inFIG. 5A as being linearly tapered, the tapered recess may also followone or more curves. For example, FIG. 5B shows another variation of cap(506) comprising a curved, tapered recess (508). Additionally oralternatively, the tapered recess may comprise one or more steps. Forexample, FIG. 5C shows a variation of cap (510) comprising a pluralityof tapered steps (512).

Additionally, in some variations, a cap may be made of a coloredmaterial that may act as a reference color for an imaging system of themeter housing. In some variations, an optical system may use the colorof the cap to calibrate color or brightness readings taken by theimaging system (e.g., by determining if the measured color of the cap isdifferent than expected). Additionally or alternatively, the color ofthe cap may allow for an imaging system to identify the boundary betweenthe cap and the quantification member. This boundary may be used as areference position when visualizing the quantification member.

It should be appreciated that the sampling arrangements may comprise anyelements or combination of elements with any suitable feature orfeatures, such as those described above.

Meter Housing

The meters described here may comprise a meter housing. Generally, ameter housing may accept/receive one or more cartridges, such as thosedescribed in more detail above, allowing the meter to provide all of thecomponents necessary to perform a testing procedure (e.g., collection,transport, and analysis of a fluid sample). As noted above, the meterhousing may be configured to be disposable, or may be configured to bereusable (e.g., configured for use with multiple cartridges). The meterhousing may be configured for handheld use, but also may be configuredto temporarily attach to the body as a wearable meter. For example, insome variations the meter housing may comprise one or more straps (e.g.,such as a wrist band) or other body-attachment elements.

FIGS. 6A-6D illustrate one variation of a meter housing (600) suitablefor use with the meters described here. Specifically, FIGS. 6A-6C show afront view, a partial cross-sectional front view, and a cross-sectionalside view, respectively, of meter housing (600). FIG. 6D shows across-sectional meter housing (600) engaging a cartridge (602). As shownthere, meter housing may comprise a display (603), button (604), port(606), cartridge-receiving chamber (608), door (609), tower (610)carrying optical system (611) and light source (612), rotating element(613), activation mechanism (614), barcode reader (616), light detector(618), foil punch (620), and trigger mechanism (622). The variouscomponents of meter housing (600) may aid in the operation of the meter,and each will be described in more detail below. Although not shown inFIGS. 6A-6C, the door (609) may comprise one or morecartridge-engagement projections, such as described in more detailabove.

The meter housings described here may comprise one or more displays,such as display (603) shown in FIG. 6A. Display (603) may be used tocommunicate information (e.g., battery/power information, testingresults, number of available test sites, reminders/alarms, and the like)to a user. Additionally or alternatively, information may be conveyed toa user via one or more sounds or audio alerts, and/or one or moretactile alerts (e.g., a vibrational alert or the like). For example, insome variations the meter housing may comprise one or more speakersconfigured to relay audio information to a user (e.g., via spokenprompts or data broadcasts).

The meter housings described here may also comprise one or more buttons,levers, switches, sensors or other structures for operating the meter.For example, meter housing (600) shown in FIG. 6A may comprise a button(604). It should be appreciated that the meter housing (600) maycomprise any suitable number of buttons (e.g., zero, one, two, three, orfour or more). These buttons (or other structures such as thosementioned above) may be configured to serve any suitable function. Insome instances, one or more buttons may be configured to turn the meteron or off, wake the meter from a hibernating state, or place the meterin a hibernating state. In other instances, one or more buttons may beused to call up information from the meter (e.g., previous testingresults, information relating to the cartridge, or the like) which maybe displayed on a display and/or aurally communicated. In still otherinstances, a button or buttons may be used to input information into themeter (e.g., calibration codes, date information, or the like), whichmay be stored in a memory component of the meter housing or cartridge.In still other variations, one or more buttons may be used toauthenticate a particular user, as described in more detail below.Additionally or alternatively, one or more buttons may be used toinitiate a testing procedure, as will be described in more detail below.It should be appreciated that one button (or a number of buttons) mayserve a number of functions, such as a combinations of the actionsdescribed immediately above. Additionally, it should be appreciated thatthese actions may be achieved through any suitable device or structure(e.g., one or more levers, switches, toggles, touch screens, sensors,combinations thereof, and the like).

The meter housing may comprise memory or other internal circuitry forstoring information (e.g., testing results, calibration codes, testingprotocols, or the like). In some variations, the meter housing may beconfigured to transmit data to or otherwise communicate with one or moreexternal components (e.g., a computer, a server, or the like), therebyallowing the meter to upload or otherwise transfer data (e.g., testingdata) stored in the meter housing. This data may then be analyzed(manually or automatically), and may allow a user, physician orhealthcare provider to evaluate the effectiveness of a given treatment,drug, diet, or exercise regime in managing one or more conditions (e.g.,diabetes) of a patient. Additionally, the meter housing may beconfigured to download information or data (e.g., date and timeinformation, calibration codes, sampling protocols, software updates,hardware updates, or the like) from an external source. In somevariations, the meter housing may comprise a communication or data port(e.g., a USB port, a firewire port, or the like) for direct connectionto a computer or other device. In other variations, the meter housingmay be configured to wirelessly transmit and/or receive information froman external source, as described in U.S. patent application Ser. No.12/457,332 and titled “MEDICAL DIAGNOSTIC DEVICES AND METHODS,” thecontent of which is hereby incorporated by reference in its entirety. Instill other variations, the meter may comprise a memory card reader. Inthese variations, a user may place a memory card or chip into the readerto provide data or information to the meter housing. In some instances,the memory card may contain information specific to a particularcartridge, such as calibration codes and/or expiration information.

As illustrated in FIGS. 6A and 6C, meter housing (600) may comprise oneor more ports (606). Generally, a port (606) may provide an opening(624) in the meter housing (600) through which a fluid sample may becollected by a sampling arrangement of a cartridge. For example, a usermay place one or more skin surfaces (e.g., a portion of a finger, palm,toe, arm, leg, stomach, or the like) or other sampling sites (e.g., aportion of a vial of control fluid) against port (606) and may initiatea testing procedure (in some instances, placing a sampling site againstthe port (606) may initiate the testing procedure). During the testingprocedure, a penetration member of a sampling arrangement (not shown)may be driven through the opening (624) in port (606) to pierce orotherwise puncture the sampling site. Additionally or alternatively, oneor more portions of the sampling site may be pressed through the opening(624), where it may be pierced by the sampling arrangement.

Port (606) may comprise any suitable structure or structures, such asone or more of the arrangements described in U.S. patent applicationSer. No. 12/457,085, titled “BODY FLUID SAMPLING DEVICE—SAMPLING SITEINTERFACE,” the content of which is hereby incorporated by reference inits entirety. For example, in some variations, such as meter housing(600) illustrated in FIGS. 6A and 6C, port (606) may comprise a flexiblering (626) which may flex, bend, or otherwise move when a force isapplied to the port (606). These variations may find particular utilityin instances where it is desirable to transmit a force via a port toanother portion of the meter (e.g., a cartridge or tower), as will bedescribed in more detail below.

One or more cartridges (602) may be placed inside the meter housing(600) via cartridge-receiving chamber (608). Specifically, door (609) ofmeter housing (600) may be opened to provide access tocartridge-receiving chamber (608), and cartridge (602) may then beinserted therein. The door (609) may then be closed to hold cartridge(602) in place, as shown in FIG. 6D. The meter housing may comprise oneor more structures for aligning, engaging and/or holding the cartridgein place relative to the meter housing (600). For example, tower (610)may align or hold the cartridge in place relative to one or moreportions of the meter housing (600). For example, in variations wheretower (610) houses an imaging system (611), tower (610) may holdcartridge (602) in place relative to the imaging system (611) (e.g., viaengagement between the cartridge (602) and one or more portions of thedoor (609), as will be described in more detail below.

The meter housings described here may comprise one or more rotationelements, which may be used to rotate a cartridge relative to one ormore portions of the meter assembly. For example, in the variation ofmeter housing (600) shown in FIGS. 6A-6D above, meter housing (600) maycomprise a rotation element (613) that is rotatable relative to thetower (610). Rotation element (613) may comprise teeth (624), cogs orother structures that may engage corresponding teeth, cogs, or similarstructures of a cartridge (e.g., teeth (209) of cartridge (200) describein more detail above in relation to FIGS. 2A-2D). Thus, when a cartridge(602) is placed within meter housing (600), as shown in FIG. 6D,engagement between the rotation element (613) and the cartridge (602)may cause the cartridge (602) to rotate as rotation element (613) isrotated relative to the meter housing (and tower (610)). Rotation of thecartridge (602) may aid in indexing the cartridge, as will be describedin more detail below, and/or may place a new sampling arrangement inposition for use with a testing procedure.

In some variations, a rotation member may aid in aligning a cartridge(e.g., cartridge (602)) relative to a meter housing. For example, in thevariation of meter housing (600) described above with relation to FIGS.6A-6D, when a cartridge (602) is pushed or otherwise inserted into acartridge-receiving chamber (608), the ramped portions (625) of teeth(624) may slide along corresponding ramped portions of teeth (not show)of the cartridge (602), which may act to rotate and self-align thecartridge (602) relative to the rotation element (613). Thisself-aligning feature may reduce the dexterity needed to properlyposition a cartridge (602) relative to the rotation member. Whilerotation element (613) described above may rotate and align thecartridge, it should be appreciated that in other instances, separatemechanisms are used to rotate and align the cartridge. In still othervariations, the meter housing may comprise an alignment mechanismwithout a rotation mechanism.

When a testing procedure is initiated, it may be necessary to trigger,activate, release, or otherwise move a sampling arrangement in order tocollect a fluid sample. As such, the meter housing may comprise one ormore trigger mechanisms for activating a sampling arrangement. Invariations where a sampling arrangement is configured to be moved by aspring, the triggering mechanism may be configured to release the springfrom a stretched, compressed, wound, or otherwise constrained position.In other variations, the triggering mechanism may at least temporarilyengage a portion of the sampling arrangement to move between one or morepositions (e.g., between a pre-firing position and an extendedposition).

Trigger mechanism may be any suitable mechanism, such as those describedin U.S. patent application Ser. No. 11/529,614, which was previouslyincorporated by reference. FIGS. 8A-8C illustrate one suitable variationof a trigger mechanism (800) suitable for use with the meters describedhere. Specifically, FIGS. 8A-8C show a cross-sectional side view of acartridge cell (802) and trigger mechanism (800) comprising a two-partactivation member (804). As shown there, activation member (804) maycomprise a vacuum tube (805) and a trigger pin (806), both attached to abase member (808). The activation member (804) may be attached to and/ormoved by the meter housing (not shown). Specifically, vacuum tube (805)and trigger pin (806) may be simultaneously advanced or withdrawn viabase member (808) by one or more actuation mechanisms, and may enter acartridge cell (802) to facilitate a testing procedure. For example,activation member (804) may be moveable between three or more positions.In a first “pre-fired” position, the entirety of activation member (804)may be external to cell (802), as shown in FIG. 8A. Upon activation of atesting procedure, the activation member (804) may be moved to a secondposition, in which a portion of the vacuum tube (805) enters and atleast partially extends into cell (802) through an aperture (810) in awall of the cell (802). As activation member (804) moves into the secondposition, it should be appreciated that the vacuum tube (805) may pierceor otherwise puncture a covering material (not shown) overlying theaperture (814).

Once in the second position, vacuum tube (805) may be connected to avacuum pump and may apply vacuum pressure to cell (802). By applyingvacuum pressure to the cell (802), the vacuum tube (805) may applyvacuum pressure to a skin surface in engagement with the cell (802).After a sufficient level of vacuum has been applied to the cell (802),the activation member (804) may then be moved to a third “firing”position. In this position, trigger pin (806) may enter and at leastpartially extend into cell (802). As trigger pin (806) enters cell(802), trigger pin (806) may engage and move one or more portions of thesampling arrangement (816), such as latch (818) of hub (820). This mayrelease latch (818), allowing a spring (824) to move samplingarrangement (816) relative to cell (802), as shown in FIG. 8C. Theactivation member (804) may then be returned to its first position, anda new cell (from the same cartridge, or a different cartridge) may beplaced in alignment with the activation member (804), such that theactivation member (804) may trigger another sampling arrangement.

While both vacuum tube (805) and trigger pin (806) shown in FIGS. 8A-8Care moved by base member (808), it should be appreciated that the vacuumtube (804) and trigger pin (806) may be actuated separately. In somevariations, the vacuum and trigger pins may be moved independently ofone another. In still other variations, the activation member comprisesa single member that acts as both a vacuum tube and a trigger pin. Inthese variations, the single member may be moved from a first positionoutside of the cartridge to a second position where the member extendspartially into the cartridge. In this position, the member may apply avacuum to the cartridge. The member may then be moved to a secondposition inside of the cartridge (e.g., may be advanced further into inthe cartridge) to trigger a sampling arrangement. For example, thetrigger mechanism (107) shown in FIGS. 1A-1D and the triggeringmechanism (622) shown in FIGS. 6A-6D may each comprise a member thatacts as both a vacuum tube and a trigger pin, as described immediatelyabove.

In some variations, the meter housing may comprise one or more barcodereaders, but need not. For example, in the variation of meter housing(600) described above in reference to FIGS. 6A-6D, meter housing maycomprise a barcode reader (616). In variations in which the cartridgecomprises one or more barcodes on a surface thereof, barcode reader(616) may be configured to scan or otherwise read information containedin the barcode. When the cartridge is configured to be rotated (e.g.,via rotation element (613)) or otherwise moved relative to the meterhousing (600), the barcode reader may scan the barcodes as the cartridgeis rotated or otherwise moved.

Additionally, in some variations, the meter housing may comprise one ormore elements for puncturing, separating, moving or otherwise removingone or more portions of a covering material from a cartridge. In somevariations, such as meter housing (600) shown in FIGS. 6A-6D anddescribed in more detail above, meter housing (600) may comprise a punch(620). Punch (620) may be advanced into a cartridge cell via one or moreapertures (not shown) to break, cut, remove or move the coveringmaterial (not shown) overlying the aperture. A sampling arrangement maythen be advanced through the uncovered aperture to collect a fluidsample from a sampling site.

Also shown in FIG. 6B are light source (612) and light detector (618).Light source (612) may be configured to direct light in the direction oflight sensor (618), and may be any suitable light source, such as thosedescribed hereinthroughout. Light detector (618) may be configured tomeasure the light at a given point inside of the meter housing (e.g.,within the cartridge-receiving chamber). When a cartridge (602) isplaced inside of the meter housing (600), as shown in FIG. 6D, the lightsource (612) and light detector (618) may help check the integrity ofthe cartridge, as will be described in more detail below.

Tower

As mentioned immediately above, the meter housings described here maycomprise one or more towers or other structures for aligning or holdinga cartridge in place relative to a meter housing. In variations of meterhousings that do comprise a tower, the tower may be fixed relative tothe meter housing, or may be movable relative to the meter housing. Invariations where the tower is moveable relative to the meter housing,the tower may be moveable in any direction or directions relative to thetower. In some variations, the tower may be moveable in a lateraldirection relative to the longitudinal axis of the meter housing.Additionally or alternatively, the tower may be configured to rotaterelative to the longitudinal axis of the meter housing. Additionally oralternatively, the tower may be configured to rotate around thelongitudinal axis of the meter housing.

FIGS. 7A and 7B show one way in which a variation of tower (700) may beconfigured to both move axially to and rotate relative to a longitudinalaxis (702) of a meter housing (not shown). Specifically, FIG. 7A shows afront view of tower (700), while FIG. 7B shows a side view of tower(700) engaging with cartridge (703). Only a cross-section of cartridge(703) is shown in FIG. 7B, and cartridge (703) may comprise one or moresampling arrangements (705) such as those described in more detailabove. As shown in FIGS. 7A and 7B, tower (700) may be rotatably coupledto a pin (704) or another linearly moveable element. Pin (704) may beslidably attached to a meter housing (not shown), such that the pin mayslide axially relative to the meter housing. Due to the engagementbetween pin (704) and tower (700), when pin (704) slides along axis(702), tower moves along the axis (702). The pin (704), and with ittower (700) may move along any suitable axis or axes of the meterhousing (e.g., a longitudinal axis of the meter). Tower (700) may alsorotate around pin (704), as illustrated by arrow (722). It should beappreciated that in some instances, tower (700) may be fixedly attachedto or otherwise integrated with pin (704), and both the pin (704) andtower (700) may be configured to rotate relative to a meter housing (notshown). This rotation may help initiate one or more testing procedures,as will be described in more detail below.

The towers described here may engage one or more cartridges to hold thecartridges in place relative to the meter housing. In some instances,the tower may hold the cartridge in a fixed relation relative to theentire meter housing. In variations where the tower is moveable relativeto the rest of meter housing, the cartridge may be held in a fixedrelation relative to the tower, and may be moveable relative to the restof the meter housing. The towers described here may engage a cartridgein any suitable manner. In some variations, one or more portions of thetower may be configured to fit inside of one or more recesses of acartridge.

The variation of tower (700) shown in FIGS. 7A and 7B shows one way inwhich the towers described here may engage a cartridge. As shown there,the distal portion of tower (700) may comprise a first section (706) anda second section (708) extending from the first section (706). First(706) and second (708) sections may be configured to extend into arecess (710) of cartridge (703) to engage the cartridge (703), as shownin FIG. 7B. In the variation of cartridge (703) shown there, recess(710) may comprise a first portion (712) having a first cross-sectionalarea and a second portion (714) having a second cross-sectional area. Atleast a portion of the first section (706) of the tower (700) may havethe same exterior dimensions and/or cross-sectional shape (e.g., circle,oval, rectangular, square, or the like) as the first cross-sectionalarea of the first portion (712) of the recess (710). Additionally oralternatively, at least a portion of the second section (708) of thetower (700) may have the same exterior dimensions and/or cross-sectionalshape (e.g., circle, oval, rectangular, square, or the like) as thesecond cross-sectional area of the second portion (714) of the cartridge(703). By matching the exterior of the tower (700) to the interior ofthe cartridge recess (710), placement of the tower into recess (710) maycreate a fit between the components that minimizes movement of thecartridge (703) relative to tower (700). It should be appreciated thatin some instances (e.g., when tower (700) and recess (710) each havecircular cross-sections), the cartridge (703) may be rotated relative tothe tower (700), as will be described in more detail above.Additionally, while shown in FIGS. 7A and 7B as having first (706) andsecond (708) sections, it should be appreciated that the tower (700) maycomprise any suitable number of sections (e.g., zero, one, two, three orfour or more sections).

In some instances, the tower may comprise one or more mechanisms forlimiting or otherwise preventing axial movement between cartridge andtower. For example, in some variations, one or more sections of thetower may affect axial movement relative to a cartridge. For example, inthe variation of tower (700) described above, the second section (708)of tower (700) may have a smaller diameter than the first section (706)of tower (700). The second portion (714) of the cartridge recess (710)may have a diameter smaller than that of the first section (706) of thetower (700), but at least as large as the second section (708) of thetower (700). Accordingly, cartridge (703) may slide along tower (700) inthe direction illustrated by arrow (716), until second section (708) oftower (700) enters second portion (714) of cartridge recess (710). Sincethe second portion (714) of the recess (710) is not large enough toaccept the first section (706) of the tower (700), these portions mayabut to prevent further axial movement toward the top of tower (700).

Additionally, one or more portions of the meter housing may prevent thecartridge (703) from disengaging from tower (700). For example, a spring(not shown) or other structure may bias or push tower (700) in adirection illustrated by arrow (718). Tower may push into recess (710)until the first section (706) of the tower (700) abuts the secondportion (714) of the recess (710), which may in turn push or biascartridge (703) in direction (718). One or more internal surfaces of themeter housing (e.g., a door or wall of a cartridge-receiving chamber)may act as a stop to block movement in direction (718). As such, thetower (700) may hold the cartridge (703) against the internal surface ofthe cartridge, holding the cartridge in place and preventing thecartridge (703) from disengaging the tower (700).

When cartridge (703) is held in place relative to tower (700), one ormore forces may be applied to the cartridge (703) to move the tower(710) relative to the meter housing (not shown). For example, in someinstances, a user may apply a force (represented by arrow (720)) tocartridge (e.g., via port)) as illustrated in FIG. 7B. This force maycause the cartridge (703) and tower (700) to rotate around pin (704) inthe direction illustrated by arrow (722). This rotation may cause tower(710) to engage an activation element (724), which may in turn initiatea testing sequence, as will be described in more detail below.

As mentioned above, although a cartridge may be held in place axiallyand laterally relative to a tower, the cartridge may still be configuredto rotate around the tower. In some variations, one or more mechanismsmay be used to rotate the cartridge relative to the tower (or viceversa), as will be described in more detail below. In other variations,the cartridge may be unable to rotate relative to the tower (e.g., whenboth the tower and the cartridge recess comprise non-circularcross-sections). These variations may be useful in variations where animaging system is housed separately from the tower within a meterhousing. In some of these variations, one or more portions of the towermay be configured to rotate relative to the meter housing, therebyrotating the cartridge relative to the meter housing. For example, invariations where the tower is connected to the meter housing via a pin(e.g., such as tower (700) and pin (704) described above in relation toFIGS. 7A and 7B), the pin (or a portion of the meter housing holding thepin) may be configured to rotate the tower and cartridge within themeter housing. Additionally or alternatively, the tower may be dividedinto different segments, wherein a first segment may be configured torotate relative to one or more other segments.

As mentioned above, a meter housing may comprise one or more activationelements for initiating a testing procedure. In some variations, anactivation element may be any suitable switch or sensor capable ofresponding to one or more forces (or other stimuli) applied thereto. Anyportion of the meter may apply a force to the activation element toinitiate a testing procedure. For example, in variations where the toweris moveable relative to the meter housing, the tower may apply a forceto the activation element. For example, in the variation of tower (700)shown in FIGS. 7A and 7B and described in more detail above, rotation oftower (700) around pin (704) (e.g., by application of force (720) tocartridge (703)) may press tower (700) into activation element (722).Alternatively, the activation element (722) may be positioned such thatrotation of tower (700) around pin (704) may cause cartridge (703) tomove into contact with the activation element (722). In still othervariations, one or more activation elements may be incorporated into aport, such that when application of a force (e.g., via one or moresampling sites) to the port applies a force to the activation element.It should also be appreciated that in some variations, the meter housingneed not comprise an activation element, and a testing procedure may beinitiated in some other manner (e.g., by pressing one or more buttons)as will be described in more detail below.

The activation element may be any suitable structure. For example, theactivation element may comprise one or more force sensors. In variationswhere the activation element comprises a force sensor, the force sensormay be configured to activate a testing procedure when the force withina certain range is applied thereto. In some instances it may bedesirable to ensure that a user is pressing against the port with atleast a minimum force level. For example, placing a skin surface againsta port with a force greater than about 200 gram-force may help toincrease blood flow to the area. As such, the force sensor may beconfigured to initiate a testing sequence once the force applied theretoindicates that the force applied to the port reaches a predeterminedminimum level. Additionally, it may be desirable to set a maximum forcelevel that will initiate a testing procedure. For example, if a skinsurface is applied to a port with too high of a force (e.g., greaterthan about 500 gram-force) the increased pressure between the skinsurface and the port may force blood away from the sampling site. Thus,in some variations, a force sensor will not initiate a testing sequenceif the force applied to the force sensor is above a certain level. Itshould be appreciated that the force sensor may be configured toinitiate a testing sequence in any suitable force range applied to theport (e.g., at least about 100 gram-force, at least about 200gram-force, at least about 300 gram-force, between about 100 gram-forceand 700 gram-force, between about 100 gram-force and about 600gram-force, between about 200 gram-force and about 500 gram-force,between about 250 gram-force and about 450 gram-force, or the like). Anysuitable force sensor may be used. In some variations, the force sensormay comprise one or more analog sensors or may comprise one or moredigital sensors. In some variations, the force sensor comprises a forcesensitive resistor.

In other variations, the activation element may comprise one or moreswitches. In these variations, a certain force applied to the switch maycause the switch to toggle/flip. The toggling of the switch may initiateone or more testing procedures. The force required to toggle the switchmay be any suitable force, such as those described above. The switch maybe configured to automatically toggle back once the force is removed, orthe meter housing may toggle the switch back upon completion of thetesting procedure. Additionally, in some variations, the activationelement may comprise a second switch, which may be toggled to cancel orabort a testing procedure if a user applies too much force to thecartridge. In still other variations, the activation element maycomprise one or more light beams, one or more strain gauges, one or morecapacitive touch switches, one or more Hall Effect sensors, or the like.

FIGS. 10A and 10B illustrate another variation of a tower that may beconfigured to be moveable relative to a meter housing. Specifically,FIG. 10A shows a perspective view of tower (1000). As shown there, towermay comprise central rotation pins (1002), guide protrusions (1004), andan activation protrusion (1006). As shown in FIG. 10B, tower (1000) maybe placed in a meter housing (1010) such that tower (1000) may beconfigured to move axially and/or rotate relative to a longitudinal axis(1016) of the meter housing (1010). Specifically, central rotation pins(1002) and guide protrusions (1004) may sit within or otherwise engageone or more tracks (not shown) of the meter housing (1010). Centralrotation pins (1002) may be able to rotate relative to the meterhousing, thereby allowing tower (1000) to rotate relative to meterhousing (1010). For example, when a force (represented by arrow (1102))is applied to an end of tower (1000) (e.g., via a cartridge), thecentral rotation pins (1002) may act as an axis of rotation around whichthe tower (1000) may rotate (as illustrated by arrow (1014)). Thisrotation may place and/or press a portion of tower (1000) (e.g.,activation protrusion (1006)) into operative engagement with anactivation element (1008), such as those described in more detail below.Additionally, central rotation pins (1002) and guide protrusions (1004)may be configured to be axially slidable relative to the meter housing(1000), and may be biased in one direction (e.g., via one or moresprings, as described in more detail above).

It should be appreciated that the central rotation pins (1002) need notbe located equidistantly between the two ends of tower (1000), but maybe placed along any suitable intermediate location. By placing thecentral rotation pins (1002) in an intermediate location, end (1018) oftower (1000) may require less lateral displacement relative to axis(1016) (i.e., in the direction of arrow (1012)) in order to place thetower (1000) in engagement with activation element (1008). This mayallow for narrower tolerances between the working components of thedevice.

While shown in FIGS. 10A and 10B as comprising guide protrusions (1004),tower (1000) need not. In variations that do comprise guide protrusions(1004), the guide protrusions (1004) may engage with the meter housing(via one or more tracts) to limit lateral displacement of the towerand/or limit the rotation of the tower. Additionally, while shown inFIGS. 10A and 10B as comprising an activation protrusion (1006), tower(1000) need not. In variations that do comprise an activation protrusion(1006), the activation protrusion may help press or otherwise engage oneor more activation elements (1008).

While the towers described above in relation to FIGS. 7A, 7B, 10A, and10B may be moveable relative to a meter housing, it should beappreciated that a tower may be fixed relative to a meter housing. Inthese variations, the tower may still engage one or more cartridges,such as described above. Application of a force to the cartridge mayinduce a deflection, deformation, or distortion in the body of thetower. This deflection may be measured to initiate a testing procedure.Specifically, an activation mechanism comprising a strain gauge may beconnected to or otherwise associated with the tower to measure the loadbeing applied to a tower, which may be representative of the force beingapplied to the cartridge. The activation mechanism may comprise anysuitable strain gauge (e.g., a full-bridge strain gauge, a half-bridgestrain gauge, or the like). When the strain gauge determines that forcebeing applied to the tower is within a predetermined range (and/orreaches a predetermined threshold), the meter may initiate a testingprocedure. In some instances, the meter may be configured to prevent theinitiation of a testing procedure if the force applied to the tower isoutside of a predetermined range.

For example, FIGS. 21A and 21B illustrate a perspective view and across-sectional side view, respectively, of one variation of a tower(2100) which may be fixed relative to a meter housing (not shown). Thetower (2100) may be fixed to the meter housing using one or morethreaded fasteners (not shown) or other mechanical fixation members. Asshown there, the tower (2100) may comprise a strain gauge (2102), suchas one or more of the strain gauges described immediately above. Acartridge (not shown) may be placed in engagement with the tower (2100),such as, for example, described above with respect to FIGS. 1A-1D andFIGS. 7A and 7B. When a force is applied to the cartridge (e.g., via aport upon application of pressure by a sampling site to the port) theengagement between the cartridge and the tower (2100) may causedeflection/deformation of the tower (2100), and this deflection may bemeasured by the strain gauge (2102). Data from the strain gauge (2102)may be carried to a printed circuit board assembly (2104) or otherprocessing assembly via an optical cable (2106) or other suitable datatransmission assembly. When the meter determines that force beingapplied to the tower/cartridge/port is within a predetermined range(and/or reaches a predetermined threshold), such as described in moredetail above, the meter may initiate a testing procedure. In someinstances, the meter may be configured to prevent the initiation of atesting procedure if the force applied to the tower is outside of apredetermined range. As shown in FIGS. 21A and 21B, the tower (2100) maycomprise an imaging system comprising a light-generating assembly (2108)and a light-receiving assembly (2110), such as one of the imagingsystems described in more detail below, but it should be appreciatedthat the towers described here need not include any imaging systems.

Cartridge Ejection

In some variations of the meter housings described here, the meterhousing may comprise one or more mechanisms for ejecting a cartridgefrom the meter housing. In some variations, the cartridge-ejectionmechanism may eject a cartridge without requiring direct user contactwith the cartridge, which may help to reduce the risk of user exposureto potentially hazardous materials (e.g., used needles or lancets). Insome variations, the cartridge may be configured to passively fall froma cartridge-receiving chamber when a door to the chamber is opened. Inother variations, one or more structures may be used to push orotherwise advance the cartridge form the chamber.

FIGS. 12A and 12B illustrate one variation of a meter housing (1200)comprising a cartridge ejection mechanism. As shown there, meter housing(1200) may comprise a cartridge-receiving chamber (1202), door (1204),and a cartridge ejection mechanism comprising button (1206) and lever(1208). In some variations the lever may have a forked or multi-prongedshape, but it should be appreciated that the lever may have any suitablesize or shape. FIG. 12A shows a perspective view of meter housing (1200)with door (1204) in an open position, and cartridge (1210) placed insideof the cartridge-receiving chamber (1202). FIG. 12B shows a front viewof meter housing (1200) with a portion of the meter housing removed.

To eject a cartridge (1210) from cartridge-receiving chamber (1202),button (1206) may be depressed or otherwise activated. Button (1206) maybe linked to lever (1208) such that activation of the button (1206)causes lever (1208) to rotate within cartridge-receiving chamber (1202).In some variations, depression of the button (1206) mechanicallyactuates the movement of lever (1208). In other variations, depressionof the button (1206) may provide a signal to one or more motors, cams,or other actuators which may in turn drive movement of the lever (1208).As lever (1208) rotates within cartridge-receiving chamber (1202), itmay press against cartridge (1210), as shown in FIG. 12B. When door(1204) is open, rotation of the lever (1208) may push the cartridge(1210) out of the cartridge-receiving chamber (1202), thereby ejectingthe cartridge (1210) from the meter housing (1200).

In some variations, button (1206) may be used to open door (1204) and toactuate lever (1208). In some of these variations, depression oractivation of the button (1206) simultaneously opens door (1204) andactuates lever (1208). In other variations, the force provided by lever(1208) to cartridge (1210) may be sufficient to cause the door (1204) tounlatch or otherwise open. In other variations, the lever (1208) may notbe actuated until the door (1204) is opened. In these variations, afirst depression or activation of the button (1206) may open the door(1204), and a subsequent depression or activation of the button (1206)(with door (1204) open) may actuate lever (1208) to eject a cartridge.It should also be appreciated that different buttons or mechanisms maybe used to open the door and to actuate the lever.

FIG. 11 depicts another variation of a meter housing (1100) comprisingan cartridge-ejection mechanism. As shown there, a portion of meterhousing (1100) is removed to reveal a cartridge-receiving chamber(1102), tower (1104), and a cartridge ejection mechanism comprising anejection pin (1106). Also shown there is a door (1108) in an openposition, and a cartridge (1110) placed inside of cartridge-receivingchamber (1102). To eject cartridge (1110) from cartridge-receivingchamber (1102), ejection pin (1106) may be advanced to engage cartridge(1110) and push cartridge (1110) out of the meter housing (1100). A usermay initiate the movement of ejection pin by depressing or activatingone or more buttons or the like, which may mechanically drive theejection pin (1106), or may send a signal to one or more motors, cams,or actuators to drive the ejection pin (1106). In variations where atrigger pin and/or vacuum pin may enter one or more cartridge cells(e.g., to activate one or more sampling arrangements, as described inmore detail above), the same trigger pin or vacuum pin may also be usedto eject the cartridge. In these variations, the cartridge and pin maybe aligned in a first orientation in which advancement of the pin causesthe pin to enter a cartridge cell (e.g., through one or more aperturesin a wall of the cell). To eject the cartridge, the cartridge and pinmay be aligned in a second orientation in which advancement of the pincauses the pin to push against one of the walls of the cartridge. Inother variations, a meter housing may comprise separate ejection,triggering, and/or vacuum pins.

Imaging System

As mentioned above, the meters described here may comprise one or moreimaging systems, but need not. Indeed, in variations where the samplingarrangement comprises one or more electrochemical quantificationmembers, it may not be necessary to have an imaging system. Invariations where the meter housing comprises an imaging system, theimaging system may act to visualize, view, detect, or otherwise measureone or more optical parameters of a portion of the meter (e.g., asampling arrangement). For example, in some variations, a cartridge maycomprise a sampling arrangement with a reagent pad that reacts with afluid sample (e.g., a blood sample, control solution) to cause a colorchange, which may be indicative of the glucose concentration of thatfluid sample. An imaging system of the meter may visualize the reagentpad during this reaction to obtain or otherwise record information aboutthe reaction (e.g., reaction rates, the amount of color change, or thelike), and this data may be analyzed to determine one or morecharacteristics of the fluid sample, such as the sample's glucoseconcentration, a hematocrit level in the sample, the volume of sampleapplied to the pad, combinations thereof, and the like. The imagingsystem may also be used to determine whether a control sample has beenapplied to a sampling arrangement, as will be described in more detailbelow.

The imaging system may be housed in any suitable portion of the meter.Generally, the imaging system is at least partially contained in themeter housing, although it should be appreciated that the cartridge maycomprise one or more portions of the imaging system. In variations wherethe meter housing comprises the imaging system, the individualcomponents of the imaging system may be housed in any suitable portionor portions of the meter. In some of these variations, one or morecomponents of the imaging system may be housed in a tower of the meter.In variations where a cartridge and tower are aligned or held in placerelative to each other, such as tower (700) and cartridge (703)described above in relation to FIGS. 7A and 7B, this engagement betweenthe tower and a cartridge may at least temporarily hold the cartridge ina fixed relation relative to the imaging system. This may make theimaging system less sensitive to patient movement, as it may be moredifficult to move the cartridge relative to the imaging system during atesting procedure.

The imaging systems described here generally comprise a light-generatingassembly and a light-receiving assembly. The light-generating andlight-receiving assemblies may be positioned in any suitable portion ofthe meter. In variations in which a meter as described here comprises atower (as described in more detail above), one or more of theseassemblies may be partially or wholly housed in the tower. In some ofthese variations, both the light-generating and light-receivingassemblies may be housed within the tower. In other variations, thelight-generating assembly may be housed within the tower and thelight-receiving assembly may be housed within another portion of themeter housing, or vice versa.

Generally, the light-generating assembly may be configured and used togenerate and direct light toward one or more portions of a meter (e.g.,one or more portions of a sampling arrangement, such as a reagent pad orthe like). The light-generating assembly generally comprises one or morelight sources. In some instances a light-generating assembly maycomprise a light source that is configured to generate light at apredetermined wavelength or within a predetermined wavelength range.Additionally or alternatively, a light-generating assembly may comprisea polychromatic light source. In other variations, a light-generatingassembly may comprise a light source which may be configured toselectively generate light at two or more different predeterminedwavelength or light within different predetermined wavelength ranges.For example, in some variations a light source comprises a RGB LED,which can selectively output red, green, and blue light. In somevariations, a light-generating assembly may comprise two or moreseparate light sources, each of which may be configured to generatelight at a predetermined wavelength or wavelength range. Accordingly,the light-generating assembly may be configured to produce light at aplurality of wavelengths, which may assist the imaging system and meterto determine an analyte concentration, or may assist the imaging systemand meter in determining the application of a control solution, as willbe described in more detail below. In some variations, alight-generating assembly may comprise a diffusor, which may spread outor otherwise scatter light generated by the light source or sources.Additionally or alternatively, a light-generating assembly may comprisea collimator, which may focus or otherwise align light generated by thelight source or sources. Additionally or alternatively, alight-generating assembly may comprise baffling or other light traps,which may help trap or otherwise remove stray light generated by thelight-generating assembly. It should be appreciated that some or all ofthe components of a light-generating assembly may be included asindividual components, while other components may be combined into amulti-purpose component. For example, some variations of thelight-generating assemblies described here may comprise an element thatincludes both a collimator and light traps.

The light-receiving assembly of the imaging systems described here maybe configured to image one or more areas of the meter. For example, invariations where the meter comprises one or more sampling arrangements,such as those described above, the light-receiving assembly may beconfigured to image one or more components of a sampling arrangement(e.g., detect and measure light reflected off of or emitted from thesampling arrangement), as will be described in more detail below. Thelight-receiving assembly may comprise one or more detectors/imagesensors, which may produce one or more electrical signals in response tolight received by the assembly. In some variations, the light-receivingassembly may comprise one or more filters, which may filter out one ormore wavelengths of light received by the light-receiving assembly.Additionally or alternatively, the light-receiving assembly may compriseone or more lenses, which may focus or otherwise redirect light withinthe light-receiving assembly. Additionally or alternatively, thelight-receiving assembly may comprise one or more mirrors which may actto redirect light through the light-receiving assembly. Additionally oralternatively, the light-receiving assembly may comprise baffling orother light traps to capture stray light within the light-receivingassembly. It should be appreciated that some or all of the components ofa light-receiving assembly may be included as individual components,while other components may be combined into a multi-purpose component.For example, in the variation of tower (2100) described above withrespect to FIGS. 21A and 21B, the light-receiving assembly (2110) maycomprise a molded optical element (2112), which may both focus andredirect light from a sampling arrangement toward a detector (2114).

FIGS. 9A and 9B illustrate one variation of imaging system (900). Asshown there, imaging system may be housed within a tower (902), and maycomprise a light-generating assembly (904) and a light-receivingassembly (906). While imaging system (900) is shown in FIGS. 9A and 9Bas having separate light-generating and light-receiving assemblies((904) and (906), respectively), it should be appreciated that theimaging system may comprise an assembly that both generates and receiveslight. Generally, light-generating assembly (904) may be configured togenerate one or more beams of light (represented by line (908)) whichmay reflect off of a pad (910) and/or other portions of a samplingarrangement. Some of the light reflected off pad (represented by line(912)) may enter light-receiving assembly (906), where it may beanalyzed, as will be described in more detail below. While shown in FIG.9 as reflecting off of pad (910), it should be appreciated that theimaging-system may visualize any structure that is in the viewing fieldof the imaging system (900) (e.g., in a position to reflect thegenerated light (908) into the light-receiving assembly (906)).

Light-generating (904) and light-receiving (906) assemblies may compriseany suitable elements or combination of elements. For example, as shownin FIG. 9A, light-generating assembly (904) may comprise a light source(914), diffuser (916), and collimator (918). The light source (914) maybe any suitable light-generating mechanism (e.g., a light-emittingdiode, gas-discharge lamp, bulb, chemical light-source, or the like).Diffuser (916) may be any suitable diffuser (e.g., a ground glassdiffuser, grey glass diffuser, opal glass diffuser, a Teflon diffuser,or the like) or the like, and may scatter or otherwise spread out thelight generated by the light source (914). Collimator (918) in turn maycomprise one or more curved mirrors or lenses (not shown) and may act toreceive the diffused light from diffuser (914) focus/align the scatteredbeams of light. Light-generating assembly (904) may further comprisebaffling (920) or other light traps between the diffuser (914) and thecollimator (918) to help remove stray light. Overall, the diffuser(914), baffling (920), and collimator (918) may transform the light fromlight-source (914) into a focused beam of light.

The generated light (908) may strike pad (910) at an angle (01) relativeto the surface of the pad. In variations where the sampling arrangementis configured to rotate relative to a cartridge, such as samplingarrangement (300) described above in relation to FIGS. 3A-3E, angle (01)may change as the pad (910) rotates with the sampling arrangement. Thus,for the purposes of discussion, angle (01) will refer to the anglebetween generated light (908) and the surface of pad (910) when the padis at its resting position. Angle (01) may have any suitable value, suchas, for example, between about 85 and about 95 degrees, between about 80degrees and about 100 degrees, and between about 75 degrees and about105 degrees, and preferably about 90 degrees. The choice angle (01) mayaffect the placement of the light-receiving assembly (906), as will bedescribed in more detail below.

As shown in FIG. 9A, light-receiving assembly (906) may comprise a firstpassage (922), mirror (924), focusing arrangement (926) comprisinglenses (928), filter (930), and detector (932). Generally, first passage(922) may receive light that is reflected off of pad (910) or anotherstructure in the viewing field of the imaging system (900). Reflectedlight (912) may then reflect off of mirror (924), where it may be passedinto focusing arrangement (926). While shown in FIG. 9 as reflecting offa mirror (924), it should be appreciated that the reflected light (912)may travel directly to the focusing arrangement without first beingreflected. In some variations, a mirror may be integrated into a surfaceof one or more focusing elements. Focusing arrangement (926) maycomprise any suitable lens or combination of lenses (928) (e.g., one ormore concave lenses and/or one or more convex lenses) capable offocusing the reflected light (912) toward detector (932).

Although shown in FIG. 9A as comprising a filter (930), light-receivingassembly (906) need not. In variations that do comprise a filter (930),filter (930) may comprise any suitable filter or filters (e.g., one ormore absorptive filters, one or more dichroic filters, one or moremonochromatic filters, or the like). Similarly, detector (932) may beany suitable detector element or elements. For example, in somevariations, the detector may comprise one or more photo diodes, CCDs, orCMOS detector elements. In variations where the detector comprises aplurality of detector elements (e.g., a plurality of CMOS detectorelements), the detector elements may be arranged into an array. Thearray may be a linear one-dimensional array, or may be a two-dimensionalarray. It should be appreciated that some or all of the components ofthe imaging systems may be combined or otherwise integrated with oneanother. For example, in some variations, a light source (e.g., alight-emitting diode) may be integrated with a diffuser. In othervariations, one or more lenses may be integrated into an opticalelement. In still other elements, a lens element and a filter elementmay be combined by coloring the lens element.

When a light-receiving assembly of an imaging element is configured toimage one or more portions of a sampling arrangement (e.g., a reagentpad), the light-receiving assembly may be positioned relative to thesampling assembly so as to help avoid the light-receiving assembly fromreceiving specular reflections when light from a light-generatingassembly strikes the imaged portions of the sampling assembly.Specifically, when light hits the imaged components of a samplingarrangement (e.g., a reagent pad, a cap), specular reflectance may occurin which beams of light striking the sampling arrangement are reflectedat an angle of reflectance equal to the angle of incidence. Thecomponents of the sampling arrangement may otherwise act as a diffusereflectance surface, scattering light from a light-generating assemblyuniformly. As long as the light-receiving assembly is not receivingspecular reflectance, the diffuse reflectance may be constant regardlessof the angle at which the light-receiving assembly receives the light.Accordingly, it may be desirable to configure the light-receivingassembly to receive the diffusely-scattered light while avoiding thespecular reflectance. When a beam of collimated light (e.g., lightgenerated by a light-generating assembly including a collimator) strikesa sampling arrangement along an axis of illumination (such as light(908) shown in FIG. 9A), the specular reflection may occur within aspecific range around an axis of reflection that at an anglecomplementary to the axis of illumination. For example, in somevariations, specular reflectance for a sampling arrangement may occurwithin about 20 degrees on either side of the axis of reflection.Accordingly, in some variations, the light-receiving assembly may bepositioned off the axis of reflection by at least about 20 degrees toavoid the specular reflectance.

For example, in the imaging system shown in FIGS. 9A and 9B, the firstpassage (922) may be configured such that only light reflected at acertain angle (02) (or a narrow range of angles) to the generated light(908) reaches mirror (924) (or other portions of the light-receivingassembly (906). Specifically, first passage (922) may comprise bafflingor other light traps (not shown) which may act to capture stray light.Angle (02) may be any suitable angle, e.g., greater than about 20degrees, greater than about 30 degrees, greater than about 40 degrees,greater than about 50 degrees, between about 15 degrees and about 25degrees, about 25 degrees and about 35 degrees, between about 35 degreesand about 45 degrees, between about 45 degrees and about 55 degrees, andthe like.

The choice of angle (02) may be partially determined by angle (01), theexpected rotation of the pad (910), the physical characteristics of pad(910) and the nature of the light produced by the light-generatingassembly (904). For example, angle (02) may be specifically chosen tominimize the chance of flaring that may occur as generated light (908)reflects off of pad (910). Specifically, when generated light (908)strikes pad (910), pad (910) may act as an imperfect lambertian surfaceto scatter light in every direction. As mentioned above, the apparentradiance of the pad may be independent of the angle at which it isviewed, except that specular reflectance may result in more intensereflection at or around an axis of reflection complimentary to the angleof incidence. For example, as illustrated in FIG. 9B generated light(908) may strike pad (910) at an angle of incidence (00. Although theapparent radiance of the pad (910) may be the same for most viewingangles, there may be some flaring (from specular reflectance) at a range(934) of angles near the angle of reflectance (Or), in which theapparent radiance of the pad may be orders of magnitude brighter.

Because flaring may affect the ability of detector (930) to image thepad (910), it may be desirable to configure the imaging system (900)such that light-receiving assembly (904) does not receive reflectedlight (912) in the range (934) of flaring as described above. As such,in some variations, angle (02) may be determined by the followingequation:

θ₂≥2*((90−θ₁)+(θ_(mr)))+½*(θr)

Where angle (θ_(mr)) is the maximum angle of rotation of pad relative tothe extended position during visualization, and (θ_(r)) is the range(934) of flaring as described in more detail above. The range (934) offlaring may depend on the nature of the generated light (908) as well asnature of the pad (910). For example, in some variations of the metersdescribed here, the sampling arrangement may be configured such thatonce pad (910) hits its point of maximum forward rotation, it may onlyrotate back about 10 degrees during visualization. Additionally, in somevariations the range of flaring may be the angle of (θ_(r))±about 15degrees (thus (θ_(r)) would be about 15 degrees. Thus, in variationswhere angle (θ₁) is about 90 degrees, angle (θ₂) may be greater thanabout 35 degrees.

Additionally, the meter may be configured such that the apparentradiance of the pad (910) as viewed by light-receiving assembly (906)does not significantly change as the pad (910) rotates. When the anglebetween a light source and the normal to a lambertian surface increases,the apparent brightness of the surface decreases. Thus, as pad (910)rotates away from the extended position, the apparent brightness of thepad may decrease. During rearward rotation, however, the pad (910) maybe brought closer to light-generating assembly (904). Because theintensity of light increases closer to a light source, the decrease ofintensity due to the rotation of the pad may be canceled by the increaseof intensity as the pad approaches the light-generating assembly.

As mentioned above, the imaging systems of the meters described here maybe configured to image one or more portions of a sampling arrangement.The imaged portions of the sampling arrangements may be controlled bythe components of the light-receiving assembly as well as the relativepositioning between the light-receiving assembly and the samplingarrangement. For example, in variations of the meters described herethat comprise a sampling arrangement which is configured to rotate orotherwise move relative to a portion of the meter (as described in moredetail above), the imaging assembly may image different portions of thesampling arrangement as the sampling arrangement moves.

In some variations, the light-receiving assembly of an imaging systemmay comprise a detector that comprises a single detector element. Inthese variations, the detector may image a single point on a samplingarrangement. For example, FIG. 14 depicts a partial view of a samplingarrangement (1400) comprising a reagent pad (1402) and a cap (1404). Animaging system (not shown) comprising a single-element detector may beconfigured to view a single-pixel viewing area (1406). The size of thisviewing area (1406) may be altered using one or more lenses or otherfocusing elements and/or modifying the relative positioning between thesampling arrangement (1400) and the imaging system. It should beappreciated that the sampling arrangement (1400) is depicted in FIG. 14for illustrative purposes, and a single-element detector may be used toimage a portion of any suitable sampling arrangement including anycomponents or combination of components, such as those described in moredetail above.

In other variations, the light-receiving assembly of an imaging systemmay comprise a detector that comprises one or more linear arrays ofdetector elements. In these variations, a detector may include anysuitable number of linear detector arrays (e.g., one linear array, twolinear arrays, three or more linear arrays, or the like), and eachlinear array may be configured to view a multi-pixel linear viewingarea. The linear detector arrays may be configured to image one or moreportions of a sampling arrangement. For example, FIG. 15A depicts onevariation of a sampling arrangement (1500) comprising a reagent pad(1502) and a cap (1504). Although only reagent pad (1502) and cap (1504)are shown in FIG. 15A, it should be appreciated that the samplingarrangement (1500) may comprise any additional element (e.g., a hub, askin penetration member) or combination of elements such as thosedescribed in more detail above. As shown in FIG. 15A, an imaging systemcomprising a linear detector array (not shown) may be configured toimage a linear viewing area (1506) divided into a plurality of pixels(1508), where each pixel (1508) corresponds to a detector element.

The viewing area (1506) of the imaging system may image any portion orportions of the sampling arrangement (1500). In some variations, theviewing area may be configured to image only a portion of reagent pad(1502). In other variations, the viewing area may be configured to imagethe reagent pad (1502) and the cap (1504). In still other variations(such as that illustrated in FIG. 15A), the viewing area may beconfigured to image the reagent pad (1502), the cap (1504), and openspace (1510) around the cap (1504). While shown in FIG. 15A as imagingthe open space (1510) on two sides of the cap (1504), the viewing area(1506) of the imaging system may image the open space (1510) on one sideof the cap (1504). When the reagent pad (1502) and cap (1504) areilluminated using an imaging system, these components may reflect lightwhile the space (1510) around it may not. FIG. 15B shows an example of atrace (1512) collected from the pixels (1508) of viewing area (1506),which reflects the amount of light collected from each of the detectorelements when illuminated by the imaging system. As shown there, trace(1512) may include a first segment (1514) corresponding to the pixelsimaging the reagent pad (1502), second and third segments (both labeledas (1516)) corresponding to the pixels imaging the cap (1504), andfourth and fifth segments (both labeled as (1518)) corresponding to thepixels imaging the open space (1510) around the cap (1504).

The meters described here may be configured to distinguish between thedifferent segments of trace (1512) during a sampling procedure. Forexample, the first segment (1514) of the trace (1512) may be used indetermination of the concentration of an analyte in a sample applied tothe reagent pad (1502), such as described in more detail below. Thesecond and third segments (1516) may assist in analysis of the sample.In some variations the cap (1504) may be used as a reference standard,and the first segment (1514) of the trace (1512) may be adjusted basedon the values of the second and third segments (1516). For example, thecap (1504) may be formed or otherwise coated with a material having aknown reflectance level. When the second and third segments (1516)(i.e., the light reflected from the cap (1504)) deviate from valuesexpected from the known reflectance level, the first segment (1514) oranother portion of the trace (1512) may be adjusted or otherwisecorrected based on this deviation. While the cap (1504) may be used as areference standard, it should be appreciated that one or more otherstructures may be used as a reference standard, as will be described inmore detail below. In these variations, the imaging system may beconfigured to adjust one or more outputs of the detector based on thedeviation between a measured reflectance and an expected reflectance ofthe reference standard component.

Additionally or alternatively, the light received from the open space(1510) may also be used to adjust the sample analysis. Because thepixels (1508) imaging the open space (1510) are not imaging the samplingarrangement (1500), light received by these pixels may be consideredstray light. Too much stray light within the meter housing may affectthat validity of one or more measurements from the imaging system.Accordingly, when the light received by the pixels imaging the openspace (1510) (e.g., fourth and fifth segments (1518) of trace (1512))reaches a certain threshold for a particular reading, the meter may takeone or more actions. In some of these variations, the meter may beconfigured to cancel a testing procedure and/or return an error value toa user. In other variations, the meter may be configured to excludespecific readings in which the light received by the pixels imaging theopen space (1510) exceeds a predetermined threshold.

While the viewing area (1506) is shown in FIG. 15A as imaging across amidline of the reagent pad (1502), an imaging system comprising a lineardetector array may visualize any suitable portion of the pad.Additionally, in variations where a sampling arrangement is configuredto move relative to the meter, movement of the pad may change the areaof the sampling arrangement that is imaged. For example, FIGS. 16A-16Cillustrate a variation of a meter (1600) comprising a samplingarrangement (1602) that is configured to rotate relative to the meter(1600). FIG. 16A shows a portion of the meter (1600), specifically atower (1604) and a cartridge (1606) housing the sampling arrangement(1602), but it should be appreciated that the meter (1600) may compriseany suitable elements or combination of elements as describedhereinthroughout. Also shown there is an imaging system comprising alight-generating assembly (1603) and a light-receiving assembly (1605).While both of these assemblies are shown in FIG. 16A as being housed inthe tower (1604), it should be appreciated that each of the assembliesmay be located in any suitable portion of the meter (1600).

A variation of the sampling arrangement (1602) is shown in FIG. 16A ascomprising a hub (1608), a skin-penetration member (1610), a reagent pad(1612), and a cap (1614), but it should be appreciated that the samplingarrangement may comprise any elements or combination of elements such asdescribed in more detail above. The sampling arrangement (1602) may beconfigured to rotate around a pivot point (1616) when triggered. Forexample, a torsional spring (not shown) may drive rotation of thesampling arrangement (1602). After the sampling arrangement (1602) hasbeen triggered, it may be configured to settle at a rest position (suchas the position of sampling arrangement (1602) in FIG. 16A) when thereare no external forces (e.g., a patient's skin) acting on the samplingarrangement (1602). The light-receiving assembly (1605) may include adetector (1618) comprising a linear array of detector elements (notshown), and the light-receiving assembly (1605) may be configured toimage one or more portions of the sampling arrangement (1602) when thesampling arrangement (1602) is in the rest position. It should also beappreciated that the light-receiving assembly (1605) may be able toimage portions of the sampling arrangement (1602) as the samplingarrangement (1602) deviates from the rest position, although the imagedportions of the sampling arrangement (1602) may change as the samplingarrangement (1602) is rotated.

In some variations, the light-receiving assembly (1605) may bepositioned and configured to image the midline (1620) of the reagent pad(1612) when the sampling assembly (1602) is in the rest position. Inother variations, such as depicted in FIG. 16B, the light-receivingassembly (1605) may be positioned and configured to image the reagentpad (1612) (and optionally cap (1614) and open space (1622) around cap(1614), as described in more detail above) with a viewing area (1624)offset from the midline (1620) of the reagent pad (1612) on a first sideof the midline (1620). When a user's skin contacts the skin-penetrationmember (1610) (such as during a sampling procedure), the contact betweenthe skin and the skin-penetration member (1610) may cause the samplingarrangement (1602) to rotate toward the light-receiving assembly (1605)(illustrated in FIG. 16A with arrow (1626)). In these instances, thesampling arrangement (1602) and the imaging system may be configuredsuch that rotation of the sampling arrangement (1602) toward thelight-receiving assembly (1605) causes the viewing area (1624) to movetoward the midline (1620) of the reagent pad (1612). Continued rotationof the reagent pad (1612) may move the viewing area (1624) past themidline (1620) to a second side of the midline (1620), as shown in FIG.16C. Because the number of pixels (1628) of the viewing area (1624) thatare imaging the reagent pad (1612) may increase as the viewing area(1624) approaches the midline of the exposed portion of the reagent pad(1612) (e.g., when the exposed portion of the reagent pad is circular oroval in shape), configuring the viewing area (1624) to transition fromone side of the midline (1620) to the other as the sampling arrangement(1620) rotates may maximize the number of pixels (1628) that can imagethe reagent pad (1612) during this rotation.

In the variation described above with respect to FIGS. 16A-16C, theviewing area (1624) imaged by the light-receiving assembly may beparallel to an axis of rotation of the sampling arrangement. It shouldbe appreciated, however, that the viewing area (1624) may beperpendicular to the axis of rotation of the sampling arrangement, ormay be otherwise angled relative to the axis of rotation of the samplingarrangement.

In some variations, the detectors described here may comprise two ormore linear arrays of detector elements. FIG. 18A shows one variation ofa sampling arrangement (1800) comprising a reagent pad (1802) and a cap(1804). An imaging system (not shown) comprising two linear detectorarrays (not shown) may image a first viewing area (1806) and a secondviewing area (1808). Two detector arrays may increase the overall numberof pixels (1810) that visualize the reagent pad (1802). The first andsecond viewing areas may be positioned on either side of a midline(1812) of the reagent pad (1802) when the sampling arrangement (1800) isin a rest position, which may compensate for movement in a directionindicated in by line (1814). Specifically, as one of the viewing areasmoves away from the midline, the other viewing area may move toward themidline.

While the first and second viewing areas are shown in FIG. 18A as beingparallel, the detector arrays may image viewing areas that a positionedat any suitable angle relative to each other. For example, FIG. 18Bshows the sampling arrangement (1800) describe above with respect toFIG. 18A. As shown there, the linear detector arrays may be configuredto image a first viewing area (1816) that is perpendicular to a secondviewing area (1818). In these variations, the first and second viewingareas may compensate for movement in multiple directions. It should beappreciated that the detectors described above may comprise any suitablenumber of linear detector arrays (e.g., one, two, or three or more), andthese arrays may have any suitable relative positioning between them. Instill other variations, a detector may comprise a two-dimensionaldetector array. For example, FIG. 19 depicts a sampling arrangement(1900) that is may be imaged by a detector (not shown) comprising atwo-dimensional detector array. As shown there, the detector array mayimage a viewing area (1902) comprising rows and columns of pixels(1904).

As mentioned above, the imaging system may be configured to use one ormore imaged portions of a sampling arrangement as a reference standard.As mentioned above, the reference standard may be formed from orotherwise include a material having a known reflectance value. The metermay be configured to correct or otherwise alter one or more measurements(such as described in more detail above) based on the variation betweenthe expected reflectance value and the actual reflectance value for thereference standard. Any suitable portion of the sampling arrangement (orother component of the meter) may be used as a reference standard. FIGS.20A-20C depict variations of sampling arrangements in which one or moreportions of the sampling arrangement may be used as a referencestandard. FIG. 20A depicts one variation of a sampling arrangement(2000) comprising a reagent pad (2002) and a cap (2004), wherein the cap(2004) may be used as a reference standard. FIG. 20B depicts anothervariation of a sampling arrangement (2006) comprising a reagent pad(2008) and a cap (2010), in which a section (2012) of the reagent pad(2008) may be used as a reference standard. Placing the referencestandard closer to the reagent pad (2008) may decrease potentialillumination variations that may occur during imaging. In somevariations the reference standard section of the reagent pad may be oneor more films attached to the reagent pad, or the reagent pad may bepartially coated or printed with a colored material. In othervariations, a reference standard section of a reagent pad may comprise areagent that produces a predetermined color change when a sample isapplied to the pad, regardless of the analyte content of the sample.While the reference standard section (2012) is shown in FIG. 20B assurrounding a periphery of the exposed reagent pad (2008), it should beappreciated that the reference standard section (2012) may be on anysuitable portion or portions of the reagent pad (2008). For example,FIG. 20C shows a variation of a sampling arrangement (2014) comprising areagent pad (2016) and a cap (2018), wherein a strip (2020) extendingalong the reagent pad (2016) may act as a reference standard.

The imaging systems described here may be configured to measure one ormore specific wavelengths (or ranges of wavelengths) when imaging one ormore portions of a meter, such as a sampling arrangement. For example,in some variations, a reagent pad may be configured to produce a colorchange when a sample containing a target analyte is applied to thereagent pad. The imaging system may be configured to measure a firstspecific wavelength reflected from the reagent pad that is associatedwith the color change. For example, in some variations a reagent pad maycontain one or more reagents which may produce a red color change when afluid sample containing a target analyte (e.g., glucose) is applied tothe reagent pad. In these variations, the meter may comprise an imagingsystem configured to measure this color change. Specifically, theimaging system may be configured to measure red light that is reflectedoff of the reagent pad. For example, the imaging system may beconfigured to measure light between about 625 and about 635 nanometers.In some variations, the imaging system may be configured to measurelight at about 630 nanometers. The meter may use these readings tocalculate the concentration of the target analyte (e.g., by using therate of change of the color of the reagent pad).

In some variations, the meter may comprise an imaging system configuredto measure two or more specific wavelengths (or ranges of wavelengths)when imaging one or more portions of the meter (e.g., a samplingarrangement). For example, in variations where a reagent pad comprisesone or more reagents which may produce a red color change when a fluidsample comprising a target analyte (e.g., glucose) is applied to thereagent pad, one or more components of the fluid sample may affect thecolor development of the reagent pad. When the fluid sample comprisesblood, red blood cells contained in the blood may contribute to the redcolor development, which may affect the concentration calculation of thetarget analyte. Because red blood cells absorb blue light, measuring theamount of blue light that is reflected off a reagent pad may allow forthe meter to estimate the hematocrit (i.e., the concentration of redblood cells) of the fluid sample. The amount of blue light reflected offa reagent pad may be inversely related to the hematocrit level of thefluid sample. Accordingly, a meter may be configured to measure both redlight and blue light from the reagent pad. When evaluating blue light,the meter may be configured to measure light between about 465 and about470 nanometers. In some of these variations, the meter may be configuredto measure light about 470 nanometers. The red light measured by themeter may be used to calculate a concentration of the target analyte,and the blue light measured by the meter may be used to provide acorrection value that may adjust the analyte concentration measurementbased on the estimated hematocrit.

In some instances, the meter may use one or more wavelengths toautomatically check for the presence of a control solution applied to asampling assembly. For example, in some variations, the reagent pad maycomprise one or more reagents which produce a specific color change whenthe control sample is applied to the reagent pad. This color change maybe used to signal to the meter that a control sample has been applied tothe reagent pad (i.e., as opposed to a fluid sample for testing). Forexample, in some instances, the control sample may be configured toproduce a blue color change in addition to a color change that may occurbased on a reaction with a target analyte (e.g., a red color change whenglucose is applied to the reagent pad). The meter may be configured tomeasure both the red light and the blue light reflected from the reagentpad. The red light may be used to calculate the concentration of atarget analyte in the control sample, while the blue may indicate thepresence of the control sample. While the level of the blue light may beused to perform hematocrit correction, as described in more detailabove, the blue color change produced by the reaction between thecontrol sample and the reagent pad may produce a reflectance valueoutside of any value expected for a body fluid sample (e.g., blood). Themeter may be configured to identify the fluid sample as a controlsolution when the blue reflection is outside of this value range. Oncethe meter has identified the fluid sample as a control solution, it maycompare the calculated concentration of the target analyte (e.g., theconcentration calculated by the red color change) to an expectedconcentration for the control solution. If the calculated concentrationdeviates from the expected concentration by more than a certain amount,the meter may be configured to re-calibrate itself or alert the userthat the control solution failed to produce a satisfactory response.

It should be appreciated that a reagent pad may create any suitablecolor change in the presence of a control solution. For example, in somevariations the control solution may yield a color change that changesthe reflectance of the pad for green wavelengths of light (e.g., about525 nanometers), or any other suitable wavelength of light (includingwavelengths in the visible spectrum, ultraviolet spectrum, infraredspectrum, and the like). It should be appreciated that different controlsolutions may result in different reflectance changes, such that themeter may identify different control solutions when applied to thereagent pads.

When a meter is configured to image lights of one or multiplewavelengths, the meter may be configured to achieve this in any suitablemanner. When a meter is configured to image light at a first wavelength,the meter may comprise a light source that is configured to output lightat the first wavelength. Additionally or alternatively, alight-receiving assembly of the meter may comprise a filter configuredto filter out wavelengths other than the first wavelength that arereceived by the light-receiving assembly. Accordingly, the detector mayreceive light of the first wavelength. In some of these variations, themeter may comprise a light source that may be configured to outputmultiple wavelengths of light, with the additional wavelengths beingremoved by the filter.

When a meter is configured to image light at two or more wavelengths(for example, a first wavelength and a second wavelength), the meter maycomprise a light source comprising a plurality of light-emittingcomponents, wherein each light-emitting component is configured tooutput a different wavelength. Each light-emitting component may be anysuitable component capable of generating a specific wavelength (e.g., alight-emitting diode or the like). For example, the light source maycomprise a first light-emitting component configured to output a firstwavelength and a second light-emitting component configured to output asecond wavelength. The light source may selectively emit light at thefirst wavelength and/or the second wavelength by selectively activatingthe first and second light-emitting components. For example, the lightsource may comprise a RGB LED package which may selectively produce red,green, and blue light. In some variations, a light-receiving assembly ofan imaging system of a meter may comprise one or more filters which mayselectively filter light outside of the two or more wavelengths. In somevariations, the meter may comprise a dual bandpass filter which mayfilter light other than the first and second wavelengths. In thesevariations, the filter may help prevent light outside of the selectedwavelengths from reaching a detector of the light-receiving assembly. Insome variations, the detector may comprise one or more photodetectors,which are configured to divide received light into different spectralcomponents. For example, the detector may comprise a RGB photodetectorwhich may measure the levels of red, blue, and green light received bythe photodetector. In these variations, polychromatic light may bereceived by the detector, yet the meter may still be able to image usingtwo or more wavelengths.

When a meter is configured to image light at two or more wavelengths,they may be imaged simultaneously or sequentially. For example, invariations where a light-receiving assembly of an imaging system thatcomprises a detector that may divide received light into differentspectral components, the meter may image light at multiple wavelengthssimultaneously. In some variations, the imaging system may be configuredto sequentially illuminate a portion of the meter (e.g., a samplingarrangement) with lights of different wavelengths.

In some variations, the imaging system may be configured to strobe alight source of a light-generating assembly off and on during imaging.When the light source is off, light received by the detector may bestray light entering the meter. The meter may be configured to subtractthe level of stray light from readings obtained from the imaging systemwhen the light source is generating light. When a meter is configured tosequentially illuminate a sampling arrangement with a plurality ofwavelengths, the light source may strobe off between illumination witheach wavelength, or may strobe off after illumination with each of thewavelengths. For example, in variations where a meter is configured toilluminate using a first wavelength and a second wavelength, the metermay be configured to illuminate using the first wavelength, strobe off,illuminate using the second wavelength, and strobe off. This may berepeated as necessary during imaging. Alternatively, the meter may beconfigured to illuminate using the first wavelength, illuminate usingthe second wavelength, then strobe off. Again, this may be repeated asnecessary to complete a concentration analysis.

User Verification

In some variations, the meter housing may comprise one or moreuser-verification mechanisms. In these variations, the meter may beconfigured such that it will only “unlock” (e.g., allow a user toperform one or more meter functions, such as performing a samplingprocedure or accessing user data) when an authorized user properlyactivates the user-verification mechanism. User-verification mechanismsmay be useful in instances where it may be desirable to prevent orotherwise limit a meter from being used or otherwise activated by anunintended user. In these instances, a meter may be intended to be usedand/or activated by a single user, or may be intended to be used and/oractivated by a specific group of users. For example, in a healthcaresetting (e.g., a hospital, clinic, or the like), a group of patients mayeach have individual meters, and a user-verification mechanism mayprevent one patient from inadvertently using another patient's meter. Inother instances, it may be desirable to allow a healthcare provider tounlock a meter.

The meters described here may comprise any suitable user-verificationmechanism. For example, in some variations, a meter may comprise afingerprint scanner, and may be configured to store reference datarelating to the fingerprint scans for one or more authorized users. Thisreference data may be obtained by scanning the fingerprints of one ormore authorized users using the fingerprint scanner, or may be importedto the device memory via one or more memory cards, data connections, orthe like. In order to unlock the meter, the meter may prompt a user toplace a finger on the fingerprint scanner. After scanning the user'sfinger, the meter may compare the scanned information with the storedauthorization data. If the meter determines that the scanned fingerprintis that of an authorized user, the meter may be configured to unlock.

In other variations, a meter may comprise a voice-activateduser-verification mechanism. In some of these variations, the meter maybe configured to obtain a voice sample from a potential user, andcompare that voice samples previously collected from authorized users.In these variations, the meter may be configured to obtain the initialvoice samples from the authorized users. In others of these variations,the user-verification mechanism may require a user to speak a certainword or sound (i.e., a verbal password) in order to unlock the device.In other variations, the user-verification mechanism may require a userto manually input a password or passcode (e.g., via one or more buttons,switches, or levers) to unlock the meter. In still other variations, theuser-verification mechanism may utilize one or more devices that mayinteract with the meter. For example, in some of these variations theuser-verification mechanism may require the presence of an RFID tag, keyfob, or memory card/chip in order to unlock the device. Authorized usersmay carry one or more of these tags, fobs or cards.

When an authorized user unlocks a meter using one or moreuser-verification procedures, the meter may remain unlocked for a setperiod of time (e.g., thirty seconds, sixty seconds, or the like) atwhich point it may return to a locked configuration, or may remainunlocked until one or more events occur (e.g., completion of a samplingprocedure, powering down of the device, a user input directing the meterto return to a locked configuration). It should be appreciated that whenthe device is in a locked configuration, the meter may be prevented fromrunning an indexing or verification procedure, conducting a samplingprocedure, allowing a user to access stored data, and/or allowing a userto change one or more device settings (e.g., changing the authorizeduser or users).

It should be appreciated that the meters described here may comprise anysuitable number of user-verification mechanisms (e.g., zero, one, two,three, or more). In variations where a meter comprises multipleuser-verification mechanisms, the meter may be configured to unlock onlywhen all of the user-verification mechanisms have been activated or maybe configured to unlock when a subset of user-verification mechanismsare activated. For example, in variations where a meter comprises afingerprint scanner and a password based user-verification mechanism,the meter may be configured to unlock upon entry of a correct passwordor the scanning of an authorized fingerprint, or may be configured torequire both the entry of a correct password and the scanning of anauthorized fingerprint.

As mentioned briefly above, in some instances a meter may be intendedfor use by a single user. One or more of the user-verificationmechanisms may help prevent the meter from being unlocked and/or used byanother user, which may reduce the risk of potential contamination. Forexample, when multiple users each have a meter, such as patients in ahospital or hospice care facility, a user-verification mechanism mayhelp reduce the likelihood that one user uses another's meter.Additionally, the user-verification mechanism may prevent inadvertentuse of the meter (e.g., by a child).

In other instances, a meter may be intended for use by multiple users.In these variations, the meter may track usage of the meter by differentauthorized users. In some of these variations, when the meter determinesthat the current authorized user is different from the previousauthorized user, the meter may be configured to prompt the current userto sterilize or otherwise decontaminate one or more portions of themeter housing and/or insert a new cartridge into the meter.

Meter Operation

The meters described above may be used to perform one or more testingprocedures. Generally, during a testing procedure a sampling arrangementmay be actuated or otherwise moved to collect a fluid sample from asampling site. The fluid may then interact with one or morequantification members to produce a measurable reaction. This reactionmay be measured or otherwise analyzed by the meter to provide a userwith information relating to the fluid sample. For example, the metersmay be configured to measure the glucose concentration of one or morefluid samples (e.g., a blood sample).

Initially, a user may load a cartridge (e.g., one of the cartridgesdescribed above) into the meter housing, and may activate the meter.Meter activation may comprise turning the meter on, or may comprisewaking the meter from a hibernation mode. The meter may be activatedbefore or after inserting a cartridge into the meter housing. In someinstances, insertion of a cartridge into the meter housing may activatea meter.

Once a cartridge has been inserted into the meter housing and the meterhas been activated, the meter may be configured to run one or moreprocedures to check, index, or otherwise obtain information from thecartridge. For example, in variations where the cartridge carriesinformation (e.g., via a barcode, memory chip, or the like, as describedin more detail above), the meter may be configured to read or otherwisereceive this information from the cartridge. In variations where thecartridge comprises one or more barcodes, the meter housing may beconfigured to read the one or more barcodes via one or more barcodereaders or other sensors. In some of these variations, reading the oneor more barcodes comprises rotating the cartridge relative to thebarcode scanner. Data received or read from the cartridge, such as oneor more calibration codes, may then be uploaded or otherwise integratedinto one or more algorithms for analyzing the fluid sample. In someinstances, the meter may determine that a cartridge is expired based onexpiration information received from the cartridge, and may alert theuser to insert a new cartridge.

Additionally or alternatively, the meter housing may be configured tocheck and/or index the cartridge. In some of these variations, the meterhousing may be configured to check to see if any or all of the samplingarrangements have been previously fired (inadvertently or as a part of adifferent testing procedure) and/or whether a covering material orhousing of a cartridge have been compromised. The meter may then createan index of sampling arrangements that are available for use in atesting procedure (e.g., have not been previously fired and are housedwithin a properly sealed cartridge cell) and sampling arrangements thatare unavailable for testing (e.g., have previously been fired and/or arehoused within a compromised cell). If no available testing sites areavailable, the meter may be configured to alert the user to insert afresh cartridge.

In some variations, an imaging system of a meter housing may check eachsampling arrangement to determine whether the sampling arrangement hasbeen previously fired and/or inadvertently activated. For example, insome variations of the cartridges described above, a samplingarrangement may have a pre-fired/cocked position and a post-firingposition. In the pre-fired position, a certain portion or portions ofthe sampling arrangement (e.g., a reagent pad) may be outside of theviewing field of the imaging system. Conversely, once the samplingarrangement has been fired, the same portion or portions of the samplingarrangement may rest in the viewing field of the imaging system. Duringthe checking procedure, the imaging system may visualize the interior ofthe cartridge cell to determine whether the specified portion orportions of the imaging system are in the viewing field. If thespecified portion is identified, the meter housing may index thatsampling arrangement as unavailable. The cartridge may then be rotatedsuch that the imaging system may check the remaining cartridge cells.

Additionally or alternatively, the indexing procedure may check the sealintegrity for the individual cells. For example, the variation of meterhousing (600) described above with respect to FIGS. 6A-6D may beconfigured to check the cartridge (602) seal. Specifically, when placedinside of cartridge-receiving chamber (608), a cartridge cell may sitbetween light source (612) and light detector (618). In variations wherethe cartridge comprises one or more viewing windows (not shown), thelight source (612) may be directed into the cartridge through one of theviewing windows. Conversely, one or more opaque covering materials mayprevent light from exiting the cartridge cell through any aperture. Ifone or more of the covering materials (and thus the cell seal) iscompromised (e.g., defective or previously pierced by a portion of themeter, such as a penetration member or a punch), light may exit cellthrough cartridge, where it may be detected by light detector (618). Assuch, if light detector (618) detects light (after controlling for anyambient light inside of the cartridge-receiving chamber), the meterhousing may index the cell as unavailable. The meter housing may thenrotate or otherwise move the cartridge such that the light source (612)may direct light into a new cell, thereby testing and indexing theremaining cells. Additionally, any suitable light source (e.g., one ormore light sources of an imaging system) may be used to check thecartridge seal.

As the cartridge cells are checked using one or more of the testingprocedures described immediately above, the meter housing may index eachcell as either available (e.g., ready for use) or unavailable (e.g.,compromised or previously fired). The meter housing may store thisindexing information for later use. Once the cartridge has been testedand/or indexed, the meter may be configured to enter a standby or aready position. When in a ready position, an aperture of a cartridgecell may be aligned with a port of the meter housing, such that asampling arrangement housed in the cartridge may collect a samplethrough the port. Alternatively, when in a standby position, thecartridge may be positioned in the meter housing such that the aperturesof the cartridge are out of alignment with the port. As such, theapertures may be covered or otherwise shielded by the meter housing,such that a user may be unable to access the apertures. The standbyposition thus may prevent a user from accessing used samplingarrangements, which may minimize a user's potential exposure to usedsampling arrangements and potential needle sticks. In variations wherethe meter housing is configured to rotate the cartridge, the meterhousing may rotate the cartridge between standby and ready positions.

In variations where the meter housing comprises a punch, the punch maybe used to “open” a cartridge cell (e.g., remove or otherwise break thecovering material overlaying one or more apertures of the cell) prior toplacing that cartridge cell in an active position. In some variations,the cartridge may be configured to enter a ready position immediatelyafter the cartridge has been indexed/checked. In other variations, thecartridge may be configured to enter a standby position immediatelyafter the cartridge has been checked. In these instances, the cartridgemay be moved from a standby position to a ready position by pressing oneor more buttons, triggers, or sensors on the meter housing. Invariations comprising a punch, the punch may align with an aperture of acartridge cell when the meter is in a standby position. Preferably, anavailable sampling arrangement may be placed in alignment with thepunch, such that the punch is ready to open the cartridge without firstneeding to rotate the cartridge.

Once the meter is in a ready position, a user may then initiate atesting procedure. If a user does not initiate a testing procedurewithin a preset amount of time, the meter may return to the cartridge toa standby position and enter a hibernation mode. A user may initiate atesting procedure in any suitable manner. In some variations, a user mayinitiate a testing procedure manually by pressing or otherwiseactivating a button, switch, lever, or sensor. Additionally oralternatively, a user may initiate a testing procedure by pressing asampling site against a port of the meter. For example, where the meterhousing comprises a moveable tower, such as tower (700) described inmore detail above with respect to FIGS. 7A and 7B, pressure applied tocartridge via the port may cause a portion of the tower or cartridge toengage an activation element, such as those described above. Theengagement between the tower or cartridge and the activation element mayinitiate the testing procedure. Similarly, in variations where the metercomprises a fixed tower, pressure applied to cartridge via the port maycause a strain, deflection, or other deflection in the tower, which maybe measured or sensed by an activation element such as a strain gauge.As mentioned above, an activation element may require a certain force orpressure to be applied thereto before initiating the testing procedure.In these variations, a testing procedure may be initiated when a certainforce or pressure has been applied to the tower and/or cartridge (e.g.,via port) for a predetermined period of time.

During a testing procedure, the meter may collect and analyze a fluidsample. First, a user may place a sampling site (e.g., one or more skinsurfaces) against a port. In some variations, the meter may beconfigured to apply vacuum, positive pressure, mechanical stimulation,and/or heat to the sampling site. Any of these stimuli may be appliedbefore, during, or after collection of the fluid sample. For example, insome variations, a vacuum tube (such as vacuum tube (805) describedabove in relation to FIGS. 8A and 8B) may penetrate or otherwise enterthe cartridge cell to apply vacuum to the sampling site. One or moresensors in the meter may monitor and/or control the pressure applied bythe vacuum site. After applying a target pressure (or otherstimulus/stimuli) for a desired period of time, the meter may activate asampling arrangement to collect a fluid sample. Any suitable triggermechanism, such as those described above, may trigger/activate thesampling arrangement. Once triggered, the sampling arrangement may moveto pierce, puncture or otherwise penetrate the sampling site, and obtaina fluid sample therefrom. The fluid sample may be transported (e.g.,pulled through the bore of a needle and/or spread across amicropatterned surface) such that the fluid sample contacts and reactswith a quantification member (e.g., a reagent pad). In some variations,the meter may be configured to determine whether the samplingarrangement has collected a sufficiently large sample, such as describedin U.S. patent application Ser. No. 12/457,331, the entire content ofwhich is hereby incorporated by reference. This reaction may produce oneor more measurable results, which may be measured and analyzed by thesampling arrangement. In some variations, one or more imaging systems,such as those described above, may be used to measure the reactionbetween the fluid sample and the quantification member. Additionally,the meter may be configured to analyze the measured data using one ormore methods or algorithms, such as those described in U.S. patentapplication Ser. No. 11/239,122, titled “ANALYTE DETECTION DEVICES ANDMETHODS WITH HEMOTCRIT/VOLUME CORRECTION AND FEEDBACK CONTROL,” thecontent of which is hereby incorporated in its entirety, and thosedescribed in U.S. patent application Ser. Nos. 12/457,332 and12/222,724, the contents of each were previously incorporated byreference. The meter may then store the results of the analysis and/ormore communicate this information to a user (e.g., via a display oraurally).

In variations where vacuum is applied to a sampling site, the vacuum maybe modulated or changed to improve collection of a fluid sample by thesampling arrangement. For example, in instances when the sampling siteis a skin surface, the application of vacuum may raise the skin surface,which may pull the skin surface toward and/or into the cartridge cell.During some testing procedures, a penetration member of a samplingarrangement may come to rest in a position that may hinder or otherwiseimpede the ability of the penetration member to collect blood from theskin surface. To help prevent this occurrence, the meter may beconfigured to modulate the pressure of vacuum applied to the skinsurface, which may alter the positioning of the skin surface relative tothe penetration member.

For example, in some variations the meter may be configured to applyvacuum to a skin site prior to activating a sampling arrangement, whichmay raise the skin surface and pull the skin surface toward the cellcartridge. The vacuum pressure may be maintained as the samplingarrangement is activated, and a fluid sample is collected. If after acertain period of time (e.g., about five seconds, about ten seconds, orthe like) the meter determines that the sampling arrangement has notcollected a sufficiently large fluid sample, the meter may be configuredto alter the vacuum pressure. For example, in some variations, the metermay be configured to partially reduce the pressure or turn off thevacuum, which may cause the skin to relax and lower. In some variations,this may reposition the penetration member within the punctured skinsurface, which may alter or otherwise increase the flow of blood to thesampling site. In some variations, the meter may be configured tore-apply vacuum to the skin surface after a certain amount of time(e.g., about one second, about two seconds, about three seconds, or thelike), which may re-raise the skin surface relative to the penetrationmember. It should also be appreciated that in some instances, modulationof the vacuum may comprise increasing the vacuum pressure. In stillother variations, the vacuum may be cyclically modulated to cyclicallyraise and lower the skin surface relative to the penetration member.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. An analyte monitoring system comprising: ananalyte meter comprising a meter housing, the meter housing comprising:a door having an open position and a closed position, the door includinga cartridge-engagement projection; and a tower including an imagingsystem at least partially housed therein, wherein thecartridge-engagement projection is configured to maintain a position ofthe cartridge relative and the imaging system.
 2. The analyte monitoringsystem of claim 1 further comprising a cartridge insertable into themeter housing and comprising a sampling arrangement.
 3. The analytemonitoring system of claim 2, wherein the cartridge is engaged with thetower upon insertion into the meter housing.
 4. The analyte monitoringsystem of claim 3, wherein the cartridge is rotatable relative to thetower.
 5. The analyte monitoring system of claim 3, wherein thecartridge-engagement projection is configured to maintain engagementbetween the cartridge and the tower when the door is in the closedposition.
 6. The analyte monitoring system of claim 5, wherein thecartridge-engagement projection is configured to press the cartridgeagainst the tower to maintain engagement between the cartridge and thetower.
 7. The analyte monitoring system of claim 3, wherein at least aportion of the tower is configured to fit inside a recess in thecartridge when the cartridge is inserted within the meter housing. 8.The analyte monitoring system of claim 1, wherein thecartridge-engagement projection comprises a spring.
 9. The analytemonitoring system of claim 2, wherein the cartridge-engagementprojection is configured to maintain alignment between the samplingarrangement of the cartridge and the imaging system.
 10. The analytemonitoring system of claim 1, wherein the cartridge-engagementprojection is on an internal surface of the door.
 11. The analytemonitoring system of claim 1, wherein the meter housing furthercomprises a cartridge-receiving chamber.
 12. The analyte monitoringsystem of claim 11, wherein the cartridge-engagement projection resideswithin the cartridge-receiving chamber when the door is in the closedposition.
 13. The analyte monitoring system of claim 1, wherein theimaging system comprises a light-generating assembly and alight-receiving assembly.
 14. The analyte monitoring system of claim 1,wherein the analyte meter is configured to position the cartridge toalign a first sampling arrangement of the cartridge with the imagingsystem.
 15. The analyte monitoring system of claim 1, wherein themaintained position of the cartridge relative to the imaging systemvisually aligns an interior of the cartridge and the imaging system viaa transparent window of the cartridge.
 16. A method of monitoring ananalyte comprising: receiving a cartridge into a cartridge-receivingchamber of a meter housing of a meter; moving a door of the meterhousing from an open position to a closed position, thereby engaging thecartridge with a tower of the meter housing of the meter, the tower atleast partially housing an imaging system, wherein, when the door is inthe closed position, a cartridge-engagement protrusion of the doorengages the cartridge and maintains a position of the cartridge relativeto the imaging system.
 17. The method of claim 16, wherein thecartridge-engagement protrusion comprises a spring and engages thecartridge by applying a force against the cartridge that biases thecartridge toward the tower.
 18. The method of claim 16, wherein themaintained position of the cartridge relative to the imaging systemvisually aligns an interior of the cartridge and the imaging system viaa transparent window of the cartridge.
 19. The method of claim 16further comprising ejecting the cartridge from the cartridge-receivingchamber when the door is in the open position by actuating acartridge-ejection mechanism.
 20. The method of claim 19, whereinactuating the cartridge-ejecting mechanism includes actuating a leverthat presses against the cartridge and pushes the cartridge out of thecartridge-receiving chamber.